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LED Combination Trailer Tail Light - Submersible - 8 Function - 21 Diodes - Square - Driver Side

LED Combination Trailer Tail Light - Submersible - 8 Function - 21 Diodes - Square - Driver Side

Item # STL3RB
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STL3RB - Red Optronics Tail Lights
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6-1/8" x 4-9/16" Square. Waterproof LED tail light acts as brake, tail, turn, side marker, side reflector, rear clearance, rear reflector, and license plate light for trailers over 80" wide. Stud mount - includes hardware. 23 Diodes. Lowest Prices for the best trailer lights from Optronics. LED Combination Trailer Tail Light - Submersible - 8 Function - 21 Diodes - Square - Driver Side part number STL3RB can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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  • Reviews (37)
  • Q & A (10)
  • Videos (2)
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Optronics Trailer Lights - STL3RB

  • Tail Lights
  • Square
  • LED Light
  • Red
  • Surface Mount
  • 6L x 4-1/2W Inch
  • Optronics
  • Non-Submersible Lights
  • Stop/Turn/Tail
  • Side Marker
  • Rear Clearance
  • Side Reflector
  • Rear Reflector
  • License Plate

6-1/8" x 4-9/16" Square. Waterproof LED tail light acts as brake, tail, turn, side marker, side reflector, rear clearance, rear reflector, and license plate light for trailers over 80" wide. Stud mount - includes hardware. 23 Diodes.


  • Square LED combination tail light serves 8 functions on trailers over 80" wide
    • Stop, tail, turn, side marker, side reflector, rear clearance, and rear reflector
    • Built-in license plate light illuminates trailers license plate
  • Sonically sealed, waterproof housing and lens unit is submersible
  • Built-in reflector removes the need for a separate reflector
  • 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 plastic housing
  • Red acrylic screw-on lens
  • Compatible with 12V DC systems
  • Stud mounts to trailer with included studs
  • 3-Wire design hardwires to trailer
  • DOT compliant


  • Configuration: driver side
    • Passenger side: STL2RB (sold separately)
  • Dimensions: 6-1/8" long x 4-9/16" tall x 2-7/8" thick
  • Distance between mounting studs (center on center): 2"
  • Diodes: 21
  • Power draw at 12.8V:
    • Stop/turn: 0.268 amps
    • Marker: 0.059 amps
  • Lifetime warranty on LEDs

Optronics STL3 Series LED Combination Tail Light Dimensions

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.

Combination Lights for Trailers Over 80" Wide

Flatbed trailer over 80" wide with combination tail lights

If a trailer is 80" or wider at its widest point, then it requires rear clearance lights in addition to basic trailer lights. These clearance lights indicate the width of the trailer when it is viewed from the back.

To meet these requirements on a flatbed utility trailer where the bed extends past the wheels, you can install combination trailer lights that include the rear clearance function. For proper mounting, the lights must be installed at the widest points on the rear of the trailer - one on each corner.

STL3RB Optronics LED Combination Tail Light for Trailers Over 80" Wide - Submersible - 8 Function - 21 Diodes - Square - Red Lens - Driver Side - Left Hand

Alternate part number: STL-3RB

California residents: click here

Video of LED Combination Trailer Tail Light - Submersible - 8 Function - 21 Diodes - Square - Driver Side

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Optronics Square LED Trailer Tail Light Installation

Speaker 1: Today you're going to be getting a look at the Optronics over eight inch wide square LED trailer tail lights. You can pick up the driver's side with part number STL3RB or you can pick up the passenger's side with part number STL2RB.These multi-function tail lights are designed for trailers over 80 inches wide. It features eight functions, rear and side reflectors. You have your stoplights, tail lights, your license plate light, your turn signal, side marker light and rear clearance light.The passenger side has all the same functions without the license plate light. The driver's side features 23 LEDs, the passenger's side has 18 LEDs, again because there is no license plate light.The attachment of the rear clearance light eliminates the need for a separate light to meet DOT requirements. They're made with an all weather molded plastic housing and a durable lens to protect against corrosion.

Compared to incandescent tail lights, LEDs are more efficient, they last longer and there's no bulbs to replace. These are going to be a nice upgrade or replacement for your trailer. Now we'll show you how easy they are to install.I've already gone ahead and removed my old lights. You can do so by removing the nuts on the back side of the light, and snipping the wires. Now it's not a bad idea to make sure the area is clean of any dirt or debris.

We can go ahead and get started by taking some wire strippers and stripping back our wire about a quarter to three-eighths of an inch.Our lights wires do come pre stripped. We're going to take just a little bit more off. Our ground wire comes pre-installed with a ring terminal, so we're all set there. Now you can install your light before you connect your wiring.If your studs don't match up with the holes on your trailer, you may have to drill. I'm going to take my license plate bracket, because we're on the driver's side, take my flat washers, line it up with the holes and then push it through.

Then I'll take the flange nuts and put them on the other side. I'll get one started and hand tightened, and then we can repeat the same process with the other stud.Once you have both hand tightened, you can take a seven-sixteenths wrench and tighten them down the rest of the way. But we sure not to over tighten, just get it nice and snug on both sides.Now we can start connecting our wires. Since we're working on the outside of the trailer, we're going to be using some heat shrink butt connectors. They're available on our website at etrailer.com.

I'm going to start with my yellow wire here, and I'm going to clean up the wire by twisting it a little bit. Then I'll take the heat shrink butt connector and put it in place. Want to make sure that the wire is not visible and crimp it together. Once it's crimped, it's a good idea to make sure that it's not going to come back out, then we can repeat the same process with our brown wire.Now we're going to connect our wires together, color for color. Brown is our running lights, our yellow is our turn signal. Connect and then crimp. Once we've got them all connected, then we can take our heat gun and shrink them down. If you need one, this also is available on our website, etrailer.com. By shrinking these down, it's going to prevent road grime, dirt, debris and moisture from getting inside.Now I'm just going to take some electrical tape and put it on my wires to help further clean up my look. Once everything's all wrapped up, just going to tuck it back behind here.Now the only thing left to do is to connect our ground wire. You'll need a self tapping screw. We're just going to go right through the middle here. Now we can repeat the same process with our passenger side. With both lights installed, now let's test them out. That's our tail lights, our brake light, on the left hand side, our brake on the right hand side, our left turn signal and our right turn signal. And here's our license plate light.And now you've had a look at the Optronics over eight inch wide square LED trailer tail lights.

Customer Reviews

LED Combination Trailer Tail Light - Submersible - 8 Function - 21 Diodes - Square - Driver Side - STL3RB

Average Customer Rating:  4.7 out of 5 stars   (37 Customer Reviews)

6-1/8" x 4-9/16" Square. Waterproof LED tail light acts as brake, tail, turn, side marker, side reflector, rear clearance, rear reflector, and license plate light for trailers over 80" wide. Stud mount - includes hardware. 23 Diodes.


I bought these as a replacement for ones on a car trailer. The factory ones died after a few months. The fit and look great. I have ordered several lights and lenses from etrailer. In stock, good price and fast shipping .. what more needs to be said. 801631


Direct replacement item. Easy to locate on line and order. Quick order receipt and shipping info. Delivered earlier than expected. Good follow up - would order from etrailer.com again. 667063


Great replacement part. The extended side lamp makes it easy to see in side view mirrors looking back. Only wish the grounding wire was internal and tapped into the mounting screw. 499683


Great product, easy to install, nice brightness, I should have purchased it when I purchased the right side. 471066


Still works great! 470641


Sent product to wrong address. Took almost two weeks. Got it in time so I could use for trailer. It was a brake light. So far working. 445106


I bought LED lights (tail,stop,turn) for my car trailer. A great improvement over the old lights. 422394


Does the job very well. The side marker extends out more than I like, but I understand that this is a design that replaces rear and rear side markers on over 80" wide trailers. 409523


Just received and installed this light today. Replaced 7 year old lights on my utility trailer hoping to not have to mess with light bulbs anymore. The light works as it should, it's nice and bright, arrived in a reasonable time frame, was packaged well, and hopefully will last. I have ordered many items from etrailer and have never had a problem. 387509


These lights are still going strong no maintenance yet 375452


Great customer service. Fast shipping. Excellent product. 350130


All ordered items worked great. Love the LED tail lights. Didn't have any problems fixing the trailer thanks to the many technical articles I found on etrailer. Not sure what happened with UPS shipping since I got notified that the parts had shipped on Saturday but didn't get them till Wednesday evening (paid extra for 3 day shipping), but definitely recommend ordering from etrailer. 341397


Quality Product, No issues after 12 months of use. 316916


They work great. LED's are such a good way to go for trailer lights. 312995

They are working great. I am a big fan of LED light for trailers.
Bruce T - 11/15/2017



Great product 310819


Great light - very durable and nice and bright. Excellent quality 301022


Easy to install; very bright lights - greater visibility. 291532


Great product ,the LED's light all the time unlike some others I had that lit when they felt like it. 279479


Great LED Light for Utility trailer use over 80 inches wide. Combination light saves the cost of a stand alone side marker / identification light. 248041

LED lights work great, look good , are very bright and reliable. Very satisfied.
Jim - 05/02/2017



Work great. Look great. 243014


The LED trailer lights arrived as promised. It was easy to install and has been a huge improvement over the original lights installed by the trailer's manufacturer. 241953


Awesome product from an awesome store. Product arrived just as described. Packing was great and looks just like I expected them to from the etrailer.com web site. Will get them installed and reviewed further. Hopefully this time, some bonehead won't back into my trailer in the parking lot of the boat ramp. Thanks etrailer for the great service. 216936

A year later and just as good as the day I installed them. Thanks etrailer.com
Ted - 08/04/2016



Had a damaged light on my trailer and decided to go with LED this time, so I replaced both sides. Very easy to install. Wires were color coded and matched my harness. Looks and works great. I was not able to find the LED in 80" plus size in local store for some reason. Only could find the 80 and under model. etrailer came through for me. Would buy from them again. 214563


Very well packed for shipping. Looks and feels like a high quality light. It is not as bright as I hoped though. I measured it with a lux meter at one meter distance. Readings were as follows: 200 lux for tail light and 425 lux for brake light. That is more than double my incandescent bulb lights which were poor. Our eye perceives light on a logarithmic scale though so double is not much. The leds have a narrow bandwidth of light which is much more annoying (attention grabbing), which is a big plus. The leds also are instant on, so no more warming up a filament to create a brake light. Overall it's a good light. 188050


super fast shipping 178676

Show More Reviews

Ask the Experts about this Optronics Trailer Lights

  • Drivers Side Light To Match Passenger Side STL2RB
    The driver's side light that matches the LED Combination Trailer Tail Light part # STL2RB is part # STL3RB. You do not want to flip the passenger side light upside down because it has a license plate light. I recommend to use the driver's side light.
    view full answer...
  • Tow Dolly Replacement Lights
    For your old car dolly, you may be interested in the Replacement Driver's Side Fender for Roadmaster RM3477 Tow Dolly with Electric Brakes - Metal # RM-922004 and # RM-922005. For similar lights you can use the Peterson Square Trailer Tail Light, 7-Function, Left Hand # 432400 and # 432200. For light from the sides instead of reflectors, you can use the Over 80" Wide, Square LED Trailer Tail Light, 7-Function, 18 Diode, Right Hand # STL2RB and left hand # STL3RB.
    view full answer...
  • Fender and Trailer Light Recommendations for a 7 x 10 foot Utility Trailer
    After looking at all the lights you referenced you should be good for trailer lights on your 7 by 10 foot utility trailer. You might check your local DOT though just to be sure as regulations can vary by area. Single Axle Trailer Fender - 16 Gauge Steel - 13inch to 14inch Wheels # F775X28-1R Over 80inch Wide, Square LED Trailer Tail Light, 7-Function, 18 Diode, Right Hand # STL2RB Over 80inch Wide, Square LED Trailer Tail Light with License Plate Light, 8-Function, 23 Diode, LH...
    view full answer...
  • Square LED Trailer Lights and 5-Way Wiring Harness for a Wesco Boat Trailer
    Over or under 80 means 80 inches of width. There are certain lighting requirements if the trailer is more than 80 inches wide. Trailers that are less than 80 inches wide can still use lights that are indicated as over 80 inch. Since you need a 5-way wiring harness I recommend getting the lights separately, # STL8RB and # STL9RB, and then getting # A25W5B for the harness. This is a 5-Way wishbone harness. That means that the running light pin has 2 wires for running lights on each side...
    view full answer...
  • Options to Replace Square Tail Lights with LED lights for Over 80 Inch and Under 80 Inch Trailers
    If your trailer came with the square Peterson lights then you can use the Submersible LED Trailer Light Kit, # TLL9RK. The Over 80 designation that you see is a federal guideline for trailers that are over 80 inches wide, and extra lighting is required for these trailers. You should check federal and state lighting guidelines if you are not sure that your trailer has the correct lighting installed on it. At this time we do not have an LED version of the Over 80 inch square tail light...
    view full answer...
  • Replacement Square Multifunction LED Tail Light for Towsmart 1400
    For a replacement passenger side tail light for your Towsmart LED light I recommend using the LED Combination Trailer Tail Light - Submersible - 7 Function - 18 Diodes - Square - Passenger Side # STL2RB because of the high quality you get with Optronics lights (check out all of the 5 star reviews). This light measures 6-1/8" long x 4-9/16" tall x 2-7/8" thick and is submersible, so it would also work on a boat trailer if that is your application. If you also need a driver's side light you...
    view full answer...
  • Recommended LED Trailer Lights to Replace Some Incandescent Trailer Lights on Large Trailer
    You absolutely can mix LED and Incandescent lights on your trailer. For your PM444 replacements, I recommend the Optronics Over 80" Wide, Square LED Trailer Tail Light, 7-Function, 18 Diode, Right Hand # STL2RB and Left Hand # STL3RB. The LED lights will draw less power and will also get rid of the bulb replacement hassle you mentioned. In rare cases you may experience hyperflashing with LED lights. If this happens when you install these lights, you can simply add a load resistor...
    view full answer...
  • Does the Replacement Tail Light Lens # AL8RB-1G Go to a Light with License Plate Function
    The Replacement Tail Light Lens for STL2RB and STL3RB # AL8RB-1G is a replacement for both the Optronics Right Hand # STL2RB and Left Hand # STL3RB lights as is indicated by the title. The part # STL3RB does have the license plate light function built-in to it.
    view full answer...
  • Version of the License Plate Light part # STL2RB with License Plate Light Below it
    The matching drivers side light to the part # STL2RB which is part # STL3RB has the license plate light underneath it like you need.
    view full answer...
  • How Waterproof is the Over 80" Wide, Square LED Trailer Tail Light # STL2RB
    The Over 80" Wide, Square LED Trailer Tail Light # STL2RB that you referenced is designed to be a submersible light. What that means is that once you got to the boat ramp you would want to disconnect your trailer wiring from your tow vehicle and then you could back your boat trailer into the water and the lights will be totally fine. The LEDs are sealed so that water would not get to them. This light would be exactly what you need. For the left hand side you would want part # STL3RB.
    view full answer...

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Info for this part was:

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Updated by:
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Updated by:
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Video by:
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Installed by:
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