1. Trailer Lights
  2. Optronics
  3. Tail Lights
  4. Round
  5. LED Light
  6. Red
Optronics LED Trailer Tail Light - Stop, Turn, Tail - Submersible - 10 Diodes - Round - Red Lens

Optronics LED Trailer Tail Light - Stop, Turn, Tail - Submersible - 10 Diodes - Round - Red Lens

Item # STL42RB
lowest price pledge
Retail:$37.60
Our Price: $19.70
You Save: 48%
Trailer Lights
Orders above $99 qualify for Free Shipping
Shipping Weight: 0.35 lbs
Quantity: 
In Stock
Optronics LED Trailer Tail Light - Stop, Turn, Tail - Submersible - 10 Diodes - Round - Red Lens Recessed Mount STL42RB
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

5-1/2" Diameter round. Waterproof trailer light serves 3 functions: stop, turn, and tail. Durable polycarbonate lens and housing. Mounts on trailer with built-in flange. Accepts standard 3-prong plug. Lowest Prices for the best trailer lights from Optronics. Optronics LED Trailer Tail Light - Stop, Turn, Tail - Submersible - 10 Diodes - Round - Red Lens part number STL42RB can be ordered online at etrailer.com or call 800-298-1624 for expert service.
  • All Info
  • Reviews (198)
  • Q & A (46)
  • Photos
  • Why etrailer?

Optronics Trailer Lights - STL42RB

  • Tail Lights
  • Round
  • LED Light
  • Red
  • 4 Inch Diameter
  • Recessed Mount
  • Optronics
  • Stop/Turn/Tail
  • Submersible Lights

5-1/2" Diameter round. Waterproof trailer light serves 3 functions: stop, turn, and tail. Durable polycarbonate lens and housing. Mounts on trailer with built-in flange. Accepts standard 3-prong plug.


Features:

  • Red round trailer light serves 3 functions on trailers
    • Stop light
    • Tail light
    • Turn signal light
  • Sonically sealed, waterproof housing and lens unit is submersible
  • LEDs make great replacements for incandescent lights
    • Last 50 times longer
    • More efficient - provide brighter light with less power output
    • No bulbs to replace - no brittle filaments
  • Durable polycarbonate lens and housing
  • Red lens over white LEDs
  • Mounts on trailer with built-in flange - hardware not included
    • Requires a 4-1/2" round hole for installation
  • Accepts industry standard 3-prong plug (A45PB and A47PB - both sold separately)
  • DOT compliant


Specs:

  • Dimensions: 5-1/2" diameter x 1-15/16" thick
  • Distance between mounting holes (center on center): 4-1/4"
  • Diodes: 10
  • Power draw at 12.8V:
    • Stop/turn: 0.413 amps
    • Tail: 0.0.26 amps
  • LIfetime warranty on LEDs


Manufacturer Cross Reference
Light will work as an exact replacement for:
  • Truck Lite # 44326R
  • Grote # 53292
  • Peterson # M418R-2

Optronics STL42 Series 4 Inch Round LED Light with Mounting Flange Diagram

Sonically Sealed, Waterproof Trailer Light

The waterproof construction of this light makes it ideal for use on trailers that may be submerged, like a boat trailer. The housing and lens are sonically sealed together to create a single unit, which means that water will not get into the light and damage the diodes or circuit board.



STL42RB Optronics LED Trailer Tail Light - Stop, Turn, Tail - Waterproof - 10 Diodes - Round - Red Lens

Alternate part number: STL-42RB




California residents: click here



Customer Reviews

Optronics LED Trailer Tail Light - Stop, Turn, Tail - Submersible - 10 Diodes - Round - Red Lens - STL42RB

Average Customer Rating:  4.8 out of 5 stars   (198 Customer Reviews)

5-1/2" Diameter round. Waterproof trailer light serves 3 functions: stop, turn, and tail. Durable polycarbonate lens and housing. Mounts on trailer with built-in flange. Accepts standard 3-prong plug.

- STL42RB
by:

These lights worked out great. good price too! EZ install.


Comments
Still working great!!
David - 07/10/2020


- STL42RB
by:

I replaced both lights on my Ranger Trailer with these new LED lights. They fit perfect and worked great.



- STL42RB
by:

Used these to replace old lights on my horse trailer. Installation was easy and they are very bright. I had issues with a connector on my first order, but the second was just fine. I also had issues with one being dim, but found out it was my trailer plug. Once it was replaced, it was great! Would use these on another trailer if needed.



- STL42RB
by:

I love shopping at Etrailer because it's easy to find products and the way products have measurements and video review makes everything easy. Plus the fast shipping is outstanding.


Comments
Very nice and knowing it will last is great.
Robert N - 10/05/2020


- STL42RB
by:

I put these LED lights on my 1967 Scotty. They have a nice clean look, and show up so much better than the originals. The wiring process, with the plug in connections, was easy!



- STL42RB
by:

my trailer light arrived in the mail today. It was packaged very well and the light was exactly as stated. I mounted this light on my Ranger boat trailer and the fit was was perfect and works very well.. very satisfied with the service and product



- STL42RB
by:

Perfect fit, wiring as described! Perfect upgrade for our 60s Sears Tent Trailer



- STL42RB
by:

It was a direct replacement for a similar trailer light that had blown several of its LED diodes. Installation was a snap and has functioned perfectly.



- STL42RB
by:

Thanks... the light is perfect and at a great price. The other place wanted $26.00 for the same light and you charged much less. I highly recommend etrailer.com for parts.



- STL42RB
by:

They look great and are plenty bright. Don't forget to get those wiring pigtails though. These do not have any way to connect without them. No external wires, just a 3-prong connection on the housing.



- STL42RB
by:

I recently purchased a trailer tail light for my Ranger Boat/trailer. It fit perfectly and looks great. Would highly recommend etrailer for your trailer lights. I replaced a fairly expensive tail light that was not working properly...no turn signal and no brake light. The etrailer light works perfectly and looks good. It replaced the Ranger tail light and works great!



- STL42RB
by:

Very bright replaced 1 and it was so much better I bought the other side



- STL42RB
by:

100 times better than the original lights I had with traditional bulbs. With the LEDs you can see them even better during the day. Which is nice to know that people can see me at all hours of the day.



- STL42RB
by:

This was an exact replacement for the original light, and works perfectly. Simple to install. Easy to purchase. I’d recommend this website to anyone looking for trailer parts.



- STL42RB
by:

It isn’t very bright. Only about half of the lights light up. Connection is solid, but am disappointed in the brightness of the light. Would not order again.


Comments
Thank you for your review. All 10 diodes of the light should illuminate. It sounds like a classic ground issue is the culprit. These lights use a 3 wire pig tail part A45PB. It is important that the pigtail is fully seated with the connector on the light and the ground wire has a clean connection with a bare metal surface or the main ground of the trailer.
-- Etrailer Expert Heather A - 10/20/2020


- STL42RB
by:

Super Bright..



- STL42RB
by:

Easy install and works great. Thank you.


Comments
Still the brightest lights on the trailer!
Simon - 02/25/2021


- STL42RB
by:

Great lights, very bright and visible day and night, much much better than the factory bulb light. I have recommended them to our friends who have RV's Thanks etrailer



- STL42RB
by:

Used to replace incandescent sealed lights on gas delivery truck. LED lights are 100% better and brighter, you can't go wrong. Being seen is no longer a problem, even in inclement weather. Great product from a Great supplier. Order it on your time and it is their before you know


Comments
They still work great. Bright and visible day and night.
Bruce - 02/25/2018



- STL42RB
by:

bright, easy to install just what I was looking for



- STL42RB
by:



- STL42RB
by:

After my wife has been nagging me for the last few years to fix her custom 5th wheel horse trailer I finally decided to take the plunge. Replaced the old light with these great new LED lights. Super bright and look great. LED lights are very sensitive to ground. This trailer has living quarters as well and the manufacturer made it of tube aluminum then used a torch to cut holes to run the wires in the tubes. The jagged edges over time have caused numerous shorts which all had to be tracked down and wire repaired as needed. When you have a large system that may have a short you can tell when you plug the trailer into the vehicle and the engine drops rpms. This trailer has fuses that once they reach a certain temp they turn off and then will come back on after they cool off. I'm very familiar with my trailer today



- STL42RB
by:

I have used etrailer several times for various needs. I am restoring an older steel horse trailer and I wanted to replace all the lights. I did purchase what I needed from etrailer; however, the tail lights came without the wiring harnesses, the amber/ red side lights have no way to mount them. I wish that this would nave been indicated on the notes. Now I need to look into how to get the harnesses and mounts from etrailer.


Comments
We mention in the product description that the plugwiring pigtail is sold separately.
-- Etrailer Expert Mike L - 02/20/2019


- STL42RB
by:

Very good lighting



- STL42RB
by:

Exact fit and quickly arrived


25
198
Show More Reviews

Ask the Experts about this Optronics Trailer Lights

  • Correct Wiring Needed to Install Optronics Round LED Trailer Light
    To install the Optronics Round LED Light # STL42RB you can use the Optronics 3-Wire Pigtail # A45PB. This has the three 20 gauge wires for stop, turn, and tail light functions. The red wire is for stop and turn, the black for tail lights, and the white is the ground wire.
    view full answer...
  • What Size Hole Needs to Be Cut To Install the Sealed 4 inch Diameter Optronics Light STL42RB
    To install the Sealed, 4" Round LED Trailer Stop, Turn and Tail Light, Flange Mount Light # STL42RB that you referenced you will need to drill a 4-1/2 inch hole for the light to fit and the mounting holes will be 4-1/4 inches apart on center. For a pig tail harness you will want the part # A45PB.
    view full answer...
  • Availability of 3-Prong Pigtail Plugs with Load Resistors
    The Optronics Round LED Trailer Stop, Turn and Tail Light # STL42RB does use a 3-prong plug for electrical connection. We offer right-angle 10-inch pigtail plug # A47PB and straight pigtail plug # A45PB. Neither of these includes a load resistor, which can be required on some wiring systems to mimic the higher electrical resistance of standard incandescent lights. Some turn signals will hyper-flash when used with LED lights because the wiring does not "see" the load from the super-high-efficiency...
    view full answer...
  • Is Optronics LED Trailer Tail Light # STL42RB Sold Individually or In Pairs
    The Optronics LED Trailer Tail Light # STL42RB is sold individually. If you needed a pair you'd need to order a quantity of two of these. For a wiring harness you'd then need the part # A47PB and for a mounting bracket part # BK45BB and you'd be set.
    view full answer...
  • Do Trailer Lights Sometimes Ground Through Mounting Hardware
    There are quite a few trailer light assemblies that use the mounting bracket as the ground. This works because the mounting brackets typically get attached to metal surfaces that touch the trailer frame which is where the ground strap of the trailer wiring harness connects. You can run a jumper wire from the mounting hardware to the main ground wire of the trailer if you wanted to as well.
    view full answer...
  • How to Connect the # STL42RB Tail Lights to a 1958 Trailer with 2 Wire Lighting System
    The 4 inch Round Sealed LED Stop, Turn or Tail Light, item # STL42RB, uses a 3 wire pig tail, item # A47PB or # A45PB, to connect to your existing trailer wiring. The plug on the pigtail plugs into the back of the tail light and is then hard wired to your trailer wiring. It sounds as if your original tail lights were grounded to the trailer frame through their mounting studs, so a third wire was not needed. When connecting the 3 wires from the 3 wire pig tail, you will ground the...
    view full answer...
  • Round LED Trailer Tail Lights to Replace Peterson Incandescent Lights
    Three inches is small for a tail light. There aren't even any incandescent stop, tail, and turn lights as small as 3 inches. It looks like to get what you want you will need to got to a 4 inch light. If you like the Peterson lights and need a flush mount that mounts in a grommet you could use # 435800. It does use the plug-in style connector but you would still hardwire all of the wires, including the grounds, to the trailer. This light includes the grommet and pigtail. I have included...
    view full answer...
  • Can Utility Lights in Trailer Run Off Running Light Circuit Through a Switch on an Aluminum Trailer
    Yes, you can run the switch power wire to a clearance light but the trailer would have to be connected to the vehicle with the running lights on for the interior lights to have power. Aluminum does not offer the best ground so if the lights do not work you may have to run a jumper ground wire to a steel component or the main trailer connector ground. I would try it first to see if there is any problem with grounding to the aluminum surface. A fuse is not needed though you could add...
    view full answer...
  • How to Ground a Trailer LED Light that Only has 1 Wire
    If a light has just 1 wire that means that it grounds through its mounting hardware. Be sure to use steel hardware and mount the light to a clean and corrosion free bare metal surface. If there isn't a steel surface where you want to mount the light you can place a ring terminal with attached wire between the hardware and mounting surface and attach the other end of the wire to a steel surface.
    view full answer...
  • Converter Recommendation to Install Combined Taillights on a Flatbed Truck that had Separate Bulbs
    It sounds like you need to convert the separate wiring of your 1991 Nissan truck to a combined setup to work with the Round LED Taillight # STL42RB. For this you will need to get a Roadmaster Brite-Lite Wiring Converter # RM-732. You will run the wires from your vehicle to the right side of the # RM-732 by function, and then from the left side of the box you will run the corresponding left or right turn signal wire to the red wire of the # STL42RB. The tail light circuit will bypass...
    view full answer...
  • Will Each LED Taillight Need to Be Grounded Separately on Trailer
    When it comes to wiring an LED taillight like the Sealed 4" Round LED Trailer Stop, Turn and Tail Light # STL42RB with Pigtail Harness, # A45PB, the red wire is for stop and turn, the black for running lights, and the white wire will need to be attached to a clean and corrosion free bare metal surface on the trailer. As for a clearance light having two wires like the Rectangular LED Trailer Clearance and Side Marker Light, # MCL32AB, you will ground the white wire and connect the black...
    view full answer...
  • How To Mount the Optronics LED Trailer Tail Light # STL42RB
    I am not entirely sure what you are asking but the Optronics LED Trailer Tail Light part # STL42RB is a flush mount trailer light that is designed to be installed on a flat piece of metal in a 4-1/2" diameter round hole with a self tapping screw like the Self-Tapping Phillips Head part # 1131832. The thickness of the metal that the light installs in is not an issue. The overall depth of the light is 1-15/16" thick. For a pigtail harness we have two options for you, part # A45PB or part...
    view full answer...
  • Can Sealed, 4" Round LED # STL42RB be Ran as Extra Stop/Turn Signal Light
    The Sealed, 4" Round LED Trailer Stop, Turn and Tail Light, Flange Mount, 3-Function, 10 SuperDiode # STL42RB can be ran to the rear of a vehicle as additional stop/turn lights. Basically you'd just need the correct install harness like the # A47PB which you'd wire to the vehicle wiring and you'd be set.
    view full answer...
  • Sealing Up Around a Trailer Tail Light Using Tail Light # STL42RB On an Airstream Trailer
    You could use a gasket maker like # LT37464. You would just need to put a small bead of the gasket maker around the outer most flange on tail light # STL42RB. I have included a picture to show you what this would look like. You could also use silicone # 0160297 around the light and at the mounting holes after you have installed it.
    view full answer...
    Image 1 for
  • Replacement LED-Type Lights for Peterson M413S Lights
    We do offer a wide range of LED-type trailer stop/turn/tail lighting products that you can see by clicking on the included link. The Peterson M413S light is a round light with a 3-hole mounting flange similar to # STL42RB that you referenced. You can confirm this item will be a direct-fit replacement by comparing the 5-1/2-inch overall diameter to your light. The three mounting holes are spaced at 4-1/4-inches on their centers. These lights use a 3-prong pigtail plug. Use part # A45PB...
    view full answer...
  • What is the Power Draw of Optronics LED 4 Inch Round Trailer Tail Light # STL42RB
    Because tail light # STL42RB has more than one function it has more than one amperage draw rating. Brake lights and turn signals draw more power so that will be the higher draw at 0.413 amps. Running lights use less power and would be the 0.26 amps. If you have the running lights on and then step on the brake, the brake light overrides the tail light. If you have the brakes on (with or without the running lights on) the turn signal will override the brake light on that side. So the...
    view full answer...
  • Turn Signal and Brake Lights Stop Working on Trailer When Headlights are On
    This sounds like a ground issue. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light. Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The light grounds should also be attached to clean and corrosion free bare...
    view full answer...
  • Replacement Optronics 5-1/2 Inch Diameter Round LED Trailer Light
    I think the part number you have on your trailer is part # STL42RB. The other numbers may be a serial number or another number for a mold or something else. The best way to see if our light is the exact replacement is to check the specs and the mounting of the # STL42RB. The light has 10 LEDs and uses a 3-prong plug like part # A47PB for the right angle plug or part # A45PB for the straight plug. The dimensions of this light are 5-1/2 inch diameter and 1-15/16 inches deep. The mounting...
    view full answer...
  • What Size Hole Should be Drilled to Install a 4 inch Optronics Clearance Light
    You would want to drill a 4-1/2 inch hole to install the 4-inch Optronics Trailer Light # STL45RB. You will also need a Straight 3-Wire Pigtail # A45PB to wire in the # STL45RB.
    view full answer...
  • Availability of LED Amber and Red Clearance, Tail Lights, and Side Marker Trailer Lights
    The STL42RB does come in amber. It is # STL42AB. Use wiring harness # A45PB with it. For 2 inch diameter amber lights you can use # MCL50AB with # A49PB and # A54GB. For 2 inch diameter red lights you can use # MCL50RB with # A49PB and # A54GB. For amber teardrop lights, you may be able to use # CBL22AB. We also have a teardrop shape kit that you would use on the roof of a truck, # CB-15AK, but it is not LED. For red teardrop lights we also do not have an LED option but we do...
    view full answer...
  • Trailer Light And Mounting Bracket Recommendation
    The Optronics light, part # STL42RB, you are asking about uses the mounting holes in the included flange for mounting. This light features 10 Super LED lights and has a sealed, waterproof housing and lens kit. The mounting holes in the flange are spaced 4-1/4 inches apart center-to-center. We do have a mounting bracket, part # BK45BB, for a 4 inch light but the mounting holes are spaced 4 inches center-to-center. If you wished to drill the holes in the bracket to match the holes in the...
    view full answer...
  • Replacement LED Trailer Light to Reduce Power Draw
    The Optronics LED Trailer Light # STL42RB is not what I could call an exact replacement for the # ST40RB but for all purposes it will be what you're looking for. The # STL42RB is 1/8 inches larger in diameter and 3/8 inches deeper so at the most you may need to do a little filing to the opening for the light in your trailer to install it. The mounting flange is metal. There is also a Stainless Steel Trim Ring # A5TRSSB available. It does not include a gasket, however If you would...
    view full answer...
  • Newly Installed LED Trailer Lights Go Out When Brake Pedal is Pressed
    This sounds like a ground issue. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light. Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The light grounds should also be attached to clean and corrosion free bare...
    view full answer...
  • What is Needed to Replace Incandescent Lights on Trailer to LED Assemblies
    You can absolutely replace the incandescent lights on your livestock trailer with LED assemblies. Other than replacing the lights themselves, there is nothing else that you will need to do. Your existing wiring (assuming it is in good condition) can be left untouched. You will find that the new LED replacements will provide a brighter light on your trailer and also won't require near the power demand that your current incandescents need. I have attached a link that will take you directly...
    view full answer...
  • Flush Mount Stop Turn and Tail Lights for a 1982 13 Foot Scamp Travel Trailer
    I did a bit of research on your trailer and the reflect-o-lite light that you mentioned. It looks as if they are surface mount lights that are 6-7/8 inch diameter. For a replacement you could use the 7 inch round Transit LED Stop/Side Marker/Tail Light, # STL90RB, to have a somewhat original appearance, with an upgraded LED light. You could also use a surface mount like the Bargman LED, Surface Mount, Double Tail Light, # 47-84-610 which would be large enough to cover the original mounting...
    view full answer...
  • Does Sealed, 4" Round LED Trailer Tail Light STL42RB Also have Reflectors
    Trailer tail light # STL42RB has reflective properties but I recommend # STL43RBX. The mounting ring around this light is a reflective lens rather than just a black ring like with # STL42RB. I also recommend wiring harness # A47PB to plug into the back of the light.
    view full answer...
  • Backup Lights Similar To the Optronics 4 Inch Round LED Trailer Light # STL42RB
    The closest backup light that we carry to the 4 Inch Round LED Trailer Light, # STL42RB, is the 4 Inch Round LED Backup Light, # BUL11CBX. This is a 4 inch round clear back up light that has an overall diameter of 5-3/4 inches and a depth of 1-5/8 inches. This light will require a standard 2 prong plug, # A45CB, and has a reflector on the mounting flange.
    view full answer...
  • Need Amber Taillights Like the Sealed 4" Round LED Trailer Taillight # STL42RB
    When it comes to the Sealed 4" Round LED Trailer Taillights, # STL42RB, the amber version is part # STL42AB. I have included two short videos for you.
    view full answer...
  • Replacement Taillights, Wiring and 7-Way Connector for Car Hauler
    To fit the round 4-1/2 inch holes on your trailer for the rear brake lights you could use the # STL42RB as this will fit in that hole. For a pigtail harness you would also need # A45PB. For the side clearance lights you would need to enlarge the holes to 3 inch in diameter, use the # A55GB as a grommet and then use # MCL59AB for the lights and # A46PB as a wiring harness. For a replacement 7-way with 8 feet of wire for running new wire everywhere you would want the part # H20046....
    view full answer...
    Image 1 for
  • Is the Optronics Trailer Light # STL42RB Sold Individually
    The Sealed, 4" Round LED Trailer Stop, Turn and Tail Light # STL42RB that you referenced is sold individually. I attached a review video for you to check out as well.
    view full answer...

Do you have a question about this Trailer Light?




  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality trailer lights for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate trailer light information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Employee Robert G
Expert Research:
Robert G
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee John H
Expert Research:
John H
Employee Adam R
Expert Research:
Adam R
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Kathleen M
Video by:
Kathleen M
Employee Jacob H
Video by:
Jacob H
Employee Laura H
Updated by:
Laura H
Employee Sarah W
Updated by:
Sarah W
Employee Brian T
Updated by:
Brian T
Employee Hannah L
Updated by:
Hannah L
Employee Cole B
Installed by:
Cole B
Employee Andrew S
Installed by:
Andrew S
Employee Shane H
Installed by:
Shane H
Employee Chris R
Video Edited:
Chris R

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.