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Optronics Combination Trailer Tail Light - Submersilbe - 7 Function - Square - Driver Side

Optronics Combination Trailer Tail Light - Submersilbe - 7 Function - Square - Driver Side

Item # ST7RB
Our Price: $7.44
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Shipping Weight: 0.52 lbs
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Trailer Lights ST7RB - Surface Mount - Optronics
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5-1/4" x 4-9/16". Waterproof incandescent combination tail light serves 7 functions: stop, turn, tail, rear reflex, side marker, side reflex, and license plate light. Screw-on lens. Stud mount to trailer. 2-Wire design. (2) 1157 Bulbs. Great Prices for the best trailer lights from Optronics. Optronics Combination Trailer Tail Light - Submersilbe - 7 Function - Square - Driver Side part number ST7RB can be ordered online at or call 1-636-306-4830 for expert service.
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  • Reviews (107)
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Optronics Trailer Lights - ST7RB

  • Tail Lights
  • Square
  • Incandescent Light
  • Red
  • 5L x 4-1/2W Inch
  • Surface Mount
  • Stop/Turn/Tail
  • Side Marker
  • Side Reflector
  • Rear Reflector
  • License Plate
  • Submersible Lights
  • Optronics

5-1/4" x 4-9/16". Waterproof incandescent combination tail light serves 7 functions: stop, turn, tail, rear reflex, side marker, side reflex, and license plate light. Screw-on lens. Stud mount to trailer. 2-Wire design. (2) 1157 Bulbs.


  • Square incandescent trailer light serves 7 functions for trailers less than 80" wide
    • Stop, Turn, Tail, Rear Reflex, Side Marker, Side Reflex
    • Built-in license plate light illuminates trailer license plate
  • Sealed, waterproof housing and lens unit is submersible
  • Built-in reflector removes the need for a separate reflector
  • Incandescent bulbs are easy to replace
  • Shockproof socket guarantees long bulb life
  • Stud mounts on trailer with included studs
    • Gasket is included to create weathertight seal
  • Wiring design contains lead wires for power and grounds through mounting studs
  • DOT compliant


  • Configuration: driver side
    • Passenger side: ST6RB (sold separately)
  • Dimensions: 5-1/4" long x 4-9/16" wide x 2-7/8" thick
  • Distance between mounting studs (center on center): 2"
  • Number of bulbs: 2
  • Bulb type: 1157
  • Power draw at 12.8V:
    • Stop/turn: 2.5 amps
    • Tail: 1 amps
  • 3-Year warranty

Manufacturer Cross Reference
Light will work as an exact replacement for:
Uni Bond # TL5441L
Wesbar # 3006
Grote # 52632
Peterson # M441L

dimensions of light

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 circuit board is sealed, which means that water will not damage the diodes or circuit board.

ST7RB Optronics Incandescent Combination Tail Light for Trailers Under 80" Wide - Submersilbe - 7 Function - Square - Driver Side - Left Hand

Alternate part number: ST-7RB

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Optronics Combination Trailer Tail Light - Submersilbe - 7 Function - Square - Driver Side - ST7RB

Average Customer Rating:  4.8 out of 5 stars   (107 Customer Reviews)

5-1/4" x 4-9/16". Waterproof incandescent combination tail light serves 7 functions: stop, turn, tail, rear reflex, side marker, side reflex, and license plate light. Screw-on lens. Stud mount to trailer. 2-Wire design. (2) 1157 Bulbs.


Iam very pleased with everything about this order, right from the time I ordered it. You informed me superbly every step of the way. The tracking info said that it was received at the post office this morning, so around midday I went to the post office box, and there it was!! Excellent. I'm very impressed. Stan Pickett


Fit perfectly om our 13 Ft. Boston Whaler EZ Loader trailer. Easy to install.


Seems like I'm always breaking these trailer lights. Fortunately, etrailer makes it easy to get replacements delivered quickly.


These lights have worked out well. Excellent purchase for my boat trailer.


everything delivered as promised.


The Trailer Lights arrived yesterday. Easy installation, looks good, happy with the product.


Part looks good arrived fast perfect re placement


Easy to install, works as designed, affordable, and delivered within a reasonable time. I have not submerged the lights yet, so the jury is still out...but other than that, they're great.

One of the lamps does not work properly...and the amount of use it has had is minimal while also being stored inside.
Petosh - 08/30/2016


Fantastic product and easy to install!!


I purchased this Stop Light Assy. (Item # ST7RB) to replace a broken one on my trailer. The one that I bought must have been an "original" Optronic's Assy. because it was as easy and remove and replace! All I had to do was cut the old wires, remove the broken assy. Install the new Assy. and hook up the new wires and test function. Worked like a dream and NOW I know what number to order in the future for the right side or the left if they ever get broken again! Thank you so much eTrailer for being there for customer's like me!


Parts purchased 1/2, shipped 1/3, arrived 1/7 in one large, well packed box. Everything as ordered. Etrailer has excellent prices, shipping and handling.

Its all working well and Im pleased with the quality.Thanks
Pete - 01/18/2016


I haven't installed these yet on my motorcycle trailer but they are a good match for the ones I'm replacing. Quality appears to be good, especially for the price. However, these are advertised as waterproof, submersible lights yet each one has 2 open holes in the back with no seals - one where the wires go in and a lower one that appears to be a drain. I picked submersibles to minimize corrosion inside.


great price, quick shipping, great pr oduct.

fantastic no problems
James - 11/03/2021


Everything is working very well.

satisfied with your products and service. In fact, several times over the last couple years, I’ve recommended your site to friends and coworkers looking for trailer, towing, fastening gear. Keep up the good work there at Etrailer.


I put these lights on my John boat trailer a year ago and launch my boat in salt water often and they still work as good as the day I installed them. Etrailer shipped them fast and have very good customer service, I can say I am impressed with their service and will be ordering from them again.


I often buy over the internet and am often hesitant to do so because the product was not described in detail. This was not the case with the taillight I recently purchased. The item was well described and was exactly what I wanted. Fast delivery. I will do future business with


This light was to replace a broken one. It was easy to install.I received it in a timely manner.Your service was great.

The light is still working great
Jeff C - 07/23/2021


Fast service, excellent product. I have already installed it and it is working great. Can't say enough about this company and I have used them before--always excellent service. A+++++++++

Still working great after a year!
Dave - 08/09/2016


I found these taillights to be an excellent value. I have had them on my trailer for a while now and they have performed very well. I had to order a replacement due to the boat ramming into it when I was reloading the boat onto the trailer after a recent fishing trip.
etrailer is very good to deal with.


I have in the past found things at etrailer that was no where else. The newest product is perfect and fast shipping even at the discounted pricing. Thanks etrailer!!



I haven't tried the submersible aspects of these lights yet, but installation was a breeze, everything worked, and they look good. Especially nice about dealing with were good website, very reasonable shipping charges, excellent communications (several of them), and quick shipping. This is a very good company to do business with. Highly recommended.


I was greatly pleased with the web site, the product itself(an exact replacement of the lights I needed), the price and the professional way the order was processed and handled. I highly recommend using Etrailer for your next purchase.


th3e combination trailer light I order is the exact one l needed thanks for your help


It was a pleasure doing business with The people I dealt with were very helpful, the product was excellent as advertised, and the lights arrived on the day I expected them.
I will definitely contact them again if the need arises.

Show More Reviews

See what our Experts say about this Optronics Trailer Lights

  • Recommended Boat Trailer Lights For Shorelandr Brand Trailer
    We don't have the exact lights, but we do have similar ones. Without knowing all of the sizes, it is really difficult to make a recommendation. I did find the tail light dimensions, so for those I recommend the Submersible, Trailer Stop, Turn and Tail Light, 6-Function, Right Hand # ST6RB and Submersible, Trailer Stop, Turn, Tail and License Plate Light, 7-Function, Left Hand # ST7RB. For clearance lights, I've linked the page to help. Side marker lights are in this same category....
    view full answer...
  • Replacement Square Trailer Tail Light Without License Plate Light
    We do! The Optronics Combination Trailer Tail Light # ST7RB you were looking at is the driver's side with that license plate light so the equivalent of that is part # ST6RB which is designed for the passenger's side so it doesn't have the license plate light. Attached is a review video for both lights for you to check out.
    view full answer...
  • Do You Have a Replacement Tail Light For My Carson Trailer
    This taillight should work on your Carson trailer as long as the original mounting holes are 2 inches on center and your mount is steel and attached directly to the trailers frame. This light gets the ground connection through the trailer frame and mounting studs. The yellow wire goes to the left turn/brake wire and the brown wire is for the taillights. If the light on your trailer is not attached to the trailer frame and needs a ground wire attached to the frame or ran to the front of...
    view full answer...
  • Can Bulb on Optronics 7-Function Light # ST7RB Be Replaced
    In order to tell you for sure if the light bulb can be replaced we will need to determine exactly which light that you have. You will want to look on the actual light housing for the manufacture name and model number. Trailer light lens can typically be used on multiple different light housings so with just the numbers from lens I can not be certain as to which light you have. If you do determine that you have the Optronics Submersible, Trailer Stop, Turn, Tail and License Plate Light,...
    view full answer...
    Image 1 for
  • Troubleshooting No Running Lights On Boat Trailer
    I recommend to first check that your 4-way connector has a good connection with the connector on the trailer. If the 4-way connector on the vehicle has any rust or corrosion on the pins you can lightly sand that off with a fine grit sandpaper. It is also a good idea to check for bent pins on the connector. If your connectors are in good shape, I recommend to check the ground on the 4-way and make sure it is attached to a clean bare metal surface of the vehicle frame. If the ground is okay...
    view full answer...
  • Are the ST8RB and ST9RB Submersible Lights
    I have a solution for you, but neither the # ST8RB nor # ST9RB are submersible lights. Instead, you'll want to use the # ST6RB and # ST7RB - which are the submersible versions of those lights. These are still incandescent tail lights that look exactly the same, have the same dimensions and are the same 2 wire electrical system, they're just sealed up so that they can be safely used on boat trailers.
    view full answer...
  • Replacement Tail Light for 2000 TrailStar Bass Tracker Pro Boat Trailer
    I looked up some photos of a 2000 TrailStar Bass Tracker Pro Boat Trailer and it most likely uses either the Optronics Combination Trailer Tail Light part # ST16RB for passenger and part # ST17RB for driver side or the Optronics Combination Trailer Tail Light part # ST8RB for passenger side or part # ST7RB for driver. Unfortunately, you'd have to replace the entire tail light as we'd not have just the lens.
    view full answer...
  • Recommendation for Replacement Submersible Trailer Lights that Ground through Mounting Hardware
    For a similar assembly to the Wesbar units you currently have installed on your trailer, I recommend looking at the Optronics Submersible Assembly # ST6RB for the Right Hand and # ST7RB for the Left Hand. These lights measure 5-17/64 inches long, 4-9/16 inches wide and 2-7/8 inches deep. These particular assemblies are designed to be corrosion resistant and includes a gasket that will create a weathertight seal. A shockproof socket will guarantee a long bulb life and the wiring design,...
    view full answer...
  • Troubleshooting Trailer Lights Not Working When Tow Vehicle Headlights Turn On
    Typically when turning on one of the light functions causes the other lights to cut out, it signals an issue with the ground connection on the trailer; the # ST6RB and # ST7RB lights both ground independently with their mounting hardware but there should be a ground wire on the trailer. I would start by checking the ground connection there and also cleaning off the trailer connectors to make sure there isn't any dirt or debris that's causing an issue. The next thing I would check out...
    view full answer...
  • Replacement Tail Light Lens for ST7RB and ST8RB Lights
    It looks like you previously purchased the Optronics Combination Trailer Tail Light - Submersilbe - 7 Function - Square - Driver Side # ST7RB, so you can use that to replace your driver's side light or the Optronics Combination Trailer Tail Light - 6 Function - Incandescent - Red Lens - Passenger Side # ST8RB for the passenger side. If you just need to replace the lens, that part is # A8RB for the front lens and # A9RB for the side lens.
    view full answer...
    Image 1 for
  • Replacement Options for a Sealed Trailer Light with a Bad Bulb
    The Peterson 440 series trailer lights typically have 4 screws at each of the corners of the lens that allow you to remove the lens and replace the bulb. It may be possible that you have a sealed version of these lights, in which case the bulb is likely not replaceable without breaking the seal between the lens and the light housing. You will likely be better off replacing the tail lights. For a submersible light with a replaceable bulb and lens that is similar to the Peterson 440 series...
    view full answer...
  • Replacement Bulb for Peterson Trailer Taillight Assembly V540
    It looks like you have the Peterson version of the Optronics Lights # ST6RB and # ST7RB. For either of these lights, the correct replacement bulb will be # A1157B. Replacing the bulb is pretty easy actually. Just remove the 4 screws from the lens of the light assembly and the bulb will be right there for you to twist out of its socket.
    view full answer...
  • Wire Gauge Use On Optronics Combination Trailer Tail Lights # ST6RB & # ST7RB
    The Optronics Combination Trailer Tail Light Drivers Side # ST7RB and Passenger Side # ST6RB come with 20 gauge wire leads. I recommend using the Deka Heat Shrink Butt Connectors # DW05743-5 to connect the tail lights to your trailer wiring.
    view full answer...
  • Right Side Trailer Lights Not Working After Installing a Wiring Harness on 2011 Mitsubishi Endeavor
    A poor ground connection could cause one side of your trailer lights not to work. I would start by checking the ground connections on the trailer since the wiring harness that you purchased does not have a separate ground wire. The ground connections on your trailer should be clean and corrosion free. Check the ground connection for the trailer connector as well as the grounds for the trailer lights. You could also inspect the trailer side connector for any corrosion and clean or replace...
    view full answer...
  • How to Use Trailer Running Lights as Accent Lights When Connected to Campground 110 Volt Electric
    To use your trailer running lights as accent lights with the trailer plugged into 110 volts, you will need to wire in a 110 volt to 12 volt converter to the 4-Way connector on your trailer. With your trailer plugged into the campground electric, you will plug the converter into an 110 volt outlet on the trailer. Next, from the 12 volt outlet side of the converter you will need to wire a ground wire to the white (ground wire) on your 4-Way connector. Then, run a wire from the 12 volt outlet...
    view full answer...
  • Submersible/ Boat Trailer Incandescent Light Recommendation
    The Optronics Trailer Tail Light # ST31RB is considered to be a weatherproof light, which means it can withstand the occasional rain shower, and according to my contact at Optronics, it is in fact submersible. That being said, I took a look at the light and wasn't able to really notice any type of seal surrounding the bulb, so I believe we have far better options for you. If your boat trailer is less than 80 inches wide, a similarly priced gasket sealed and waterproof incandescent light...
    view full answer...
  • What are the Correct Replacement Bulbs for Optronics Trailer Lights # ST6RB and # ST7RB
    It looks like you have Optronics Lights # ST6RB and # ST7RB. For either of these lights, the correct replacement bulb will be # A1157B that you have referenced and # 30-90-194 for the side light. Trailer lights are a 2-wire system. This means that they have combined stop and turn signals on the same bulb. If the lights do not blink with the turn signals, you may need to change the running light wire with the stop/turn signal wires. Use a circuit tester like # 40376 to test the trailer...
    view full answer...
  • Recommended Inexpensive Submersible Trailer Tail Lights
    I can highly recommend the lamps I use on my PWC trailer, # ST6RB and ST7RB. The lamps are submersible, inexpensive and durable. They are also available in an LED version, # STL8RB and STL9RB. The LED versions are obviously quite a bit more expensive, but they are brighter and only use a fraction of the power that a comparable incandescent bulb would. LEDs do not burn out, you will never have to replace a bulb.
    view full answer...
  • Recommended Trailer Lights and Parts Needed to Install With Wesbar 4 Pole Flat Connector
    When using the Wesbar # W787274 you can just run a jumper wire for the running lights on the other side of the trailer; you're likely going to want to split the jacketing so that you can run the tail/blinker/brake light wires down each individual side of the trailer to allow for easier installation. If you need butt connectors you can use the Deka Heat Shrink Butt Connectors # DW05745-5 to make your wiring connections, and you'll need 14 gauge wiring to match the Wesbar harness. For lights...
    view full answer...
  • Recommendation for Sealed Lights on a PWC Trailer that is Launched in Salt Water
    I would recommend going with LED lights that have sealed units in them like the LED Submersible Trailer Stop, Turn and Tail Light, item # STL8RB and the # STL9RB, for your trailer. The inside of these lights are fully sealed for corrosion protection and you would only have to worry about sealing connections where the wires are spliced into the trailer wiring. For sealing the wire connections you can use Liquid Electrical Tape, item # SWC50122.
    view full answer...
  • Will Optronics Submersible Trailer Light ST6RB Work on Malone Kayak Trailer
    The Submersible Trailer Stop, Turn, and Tail Light # ST6RB that you referenced is a great choice to replace the existing lights on your Malone Kayak Trailer. The light housing is designed to allow water to flow in and back out of the housing while being submerged. This light has 6 functions: stop, turn, tail, rear reflex, side marker, and side reflex, and will mount on studs with 2 inch centers. For the left-hand version of this light you will want # ST7RB. For a similarly sized light...
    view full answer...
  • How to Power Trailer Lights from Battery when Not Connected to Tow Vehicle
    A battery isolator will cut off power once the solenoid is energized from another source. Diodes on the other hand only allow power to flow one way. What you will need to do is run a power wire or wires from the positive battery terminal on a trailer battery to a switch such as # PK34571. Then you would run another wire from the switch to a diode # RM-690. Then run a wire from the diode to the trailer wiring for the lights you want to power. Depending on what lights you want to use you...
    view full answer...
    Image 1 for
  • Trailer Tail Light Protector and Matching Tail Lights
    The light guard # LG440NP is designed to fit Peterson square tail lights # 432200 for the right and # 432400 for the left. A license plate light is still a good idea because you never know where you might tow the trailer! You could also use submersible lights # ST7RB for the left and # ST6RB for the right. And you might be interested in aluminum tread plate light protector # CE26051A. Since it is aluminum it will not corrode like steel.
    view full answer...
  • Can Trailer Running Lights be Powered Off of a Battery When Not Connected to a Trailer
    I do have a way that you can wire the lights on the trailer so that they will come on when connected to the tow vehicle or off of a battery on the trailer. What you will need to do is add 2 diodes, # RM-792, to the wiring set up. You will also need a switch, # D16740, and a wiring installation kit # 55151. I have included a diagram of how this should all be wired. Basically the wiring to the light will come from 2 sources; the trailer connector, and the battery via a switch. The diode...
    view full answer...
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