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Combination LED Trailer Tail Light - Submersible - 7 Function - 14 Diodes - Driver Side

Combination LED Trailer Tail Light - Submersible - 7 Function - 14 Diodes - Driver Side

Item # STL9RB
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Optronics Trailer Lights - STL9RB
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5-1/16" x 4-9/16" Square. Waterproof trailer light serves 7 functions: stop, turn, tail, rear reflex, side marker, side reflex, and license plate light. Durable plastic housing. Stud mount on 2" centers. 3-Wire design. Lowest Prices for the best trailer lights from Optronics. Combination LED Trailer Tail Light - Submersible - 7 Function - 14 Diodes - Driver Side part number STL9RB can be ordered online at or call 1-800-940-8924 for expert service.
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Optronics Trailer Lights - STL9RB

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

5-1/16" x 4-9/16" Square. Waterproof trailer light serves 7 functions: stop, turn, tail, rear reflex, side marker, side reflex, and license plate light. Durable plastic housing. Stud mount on 2" centers. 3-Wire design.


  • Square trailer light serves 7 functions
    • Stop light, turn signal light, tail light, rear reflex reflector, side marker light, side reflex reflector, license plate light
  • Built-in reflex reflector removes the need for a separate reflector
  • Sealed, waterproof construction is submersible
  • Durable surface-mount technology (SMT) construction of LED circuit board
    • Better withstands shock and vibration
    • Allows for improved heat distribution
  • LEDs make great replacements for incandescent lights
    • Last 50 times longer
    • More efficient - provide better light with less power output
    • No bulbs to replace - no brittle filaments
  • Molded plastic housing and durable acrylic lens
  • Red lens over white LEDs
  • Stud mount with included hardware
  • 3-Wire pigtail
    • White wire is the ground
    • Brown wire is for the tail lights
    • Yellow wire is for the stop and turn lights


  • Configuration: driver's side
    • Passenger's side: STL8RB (sold separately)
  • Dimensions: 5-1/16" wide x 4-9/16" tall x 2-5/8" deep
    • Light face: 4-9/16" wide x 4-9/16" tall
  • Distance between mounting studs (center on center): 2"
  • Diodes: 14
  • Power draw at 12.8V:
    • Stop light: 0.259 amps
    • Side marker light: 0.062 amps
  • Lifetime warranty on LEDS

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.

STL9RB Optronics Combination LED Taillight with License Plate Illuminator for Trailers Under 80" - Red lens - 14 Diodes

Alternate part number: STL-9RB

California residents: click here

Customer Reviews

Combination LED Trailer Tail Light - Submersible - 7 Function - 14 Diodes - Driver Side - STL9RB

Average Customer Rating:  4.9 out of 5 stars   (351 Customer Reviews)

5-1/16" x 4-9/16" Square. Waterproof trailer light serves 7 functions: stop, turn, tail, rear reflex, side marker, side reflex, and license plate light. Durable plastic housing. Stud mount on 2" centers. 3-Wire design.


Perfect replacement for factory installed lights.
Was able to use factory drilled mounting holes.
Installed in less than 45 minutes. Much brighter than original lights. I believe that they should provide many years of trouble free use.

Its been about a year, the lights have gone through all four seasons here in Minnesota and continue to function flawlessly. They have been a great investment saving me the time and effort needed to replace light bulbs.
Don - 06/21/2018


Great to deal with, one light was busted during shipping, they quickly sent me another one no questions asked . Great service d


I installed lights on boat trailer in May 2019...
Launched boat several times with water covering lights.
Stored boat and trailer outdoors all winter of 2019/2020.
April 19, 2020 I took boat and trailer to marine shop for maintenance.


Thank you for selling a reliable, quality product!

Lights still work perfectly after heavy snows during 2020 2021 winter outdoor storage.
David V - 04/21/2021


Had to replace the tail light on my motorcycle trailer that vibrated and broke on my last trip (different manufacturer). Just completed a 500 mile trip, including periods of rain. No problems at all. Grat product.


Awesome idea! I've used them for the last several years but, unfortunately, I broke the lens when I hit something. My old ones didn't have replacement lenses, my new one do. If I break them again, it will be a lot cheaper and easier just to replace the lens instead of the whole tailight.

LED Submersible Trailer Stop, Turn, Tail and License Plate Light. The LH and RH taillights that Ive been using for a year now still work perfectly theyve been submerged hundreds of times! Theyre several times brighter than my old LED lights-a real safety factor! The only thing Id like to see would be a non-license-plate version of the LH unit for states like MN that dont issue trailer license plates. I had to tape over the illuminating lights on that side. A truly great product!
Ned P - 04/16/2014


Appears to be of excellent quality and fit. Easy replacement of old bulb type lights. Everyone should retro their lights to LED's. Big safety improvement. Don't have a report on how submersible/water tight these lights will be yet.

Nothing to add, but.... awesome. they are bright and work fine on the boat trailer, even after several dunkings in the lake.
JW - 07/16/2014


Very impressed! Ordered the STL9RB and the other side twin STL8RB. Etrailer shipped the wrong twin. One phone call and 5 minutes later, the correct part was shipped!

The LED tail lights and side markers (MCL82ADB Optronics LED Surface Mount Marker/Clearance Lights with Reflex) are for a home-built cargo trailer. Decent build, waterproof, and the plastic is of a heavy gauge to last a long time in the Arizona sun. These units are equipped with LED's, and should last a long time.

Thanks etrailer!

One year in, and tail lights are still holding up well in the Arizona sun . . . . . :-
Robert B - 04/10/2019


Very nice lights for the price. They were easy to install and the mounting bolts fit right into my existing holes from my "different brand" lights that were damaged. They are very bright! Not sure if they are "truly" submersible like the add says, as the wires simply go through a manufactured hole in the back of the case, so the wiring inside must be sealed. Either way, I just filled this hole with some regular silicone caulk. As with all trailer lights I would recommend buying or making light guards, as these lights can break easily. Overall I am happy and would definitely recommend!

Thank you! The lights are great, no issues at all, and tough as nails!!! I have them on a 10k 6x10 dump trailer, that I beat the snot out of, gravel logging roads, mud, snow, ice, driving through brush. I just wish my trailer tires were as tough as those lights. Thanks again, and if I ever need anything for my trailers, I will be shopping etrailer!!!
John R - 11/06/2018


Installed this and several other lights on a new trailer. Factory lighting and wiring left a lot to be desired, and with the help of I was able to get everything fixed up like I wanted.

Lights work very well - clear and bright red tail and turn/brake lights.

All of the products I purchased its been about 2 years now are still working great. Thanks for checking in.
Jim - 12/10/2018


Looks Great! Works Great! These were added to a 14' Kaufman Dump Trailer that I wanted to use as a utility trailer also, but when completely tarped, the brake/tail/turn lights were covered. So, I added these lights to the side of the frame so that they could be seen when the trailer was securely tarped.

I still love the products purchased
Winsel S - 12/31/2016


STL9RB & STL8RB Trailer tail-lights. Removed old standard bulb tail-lights, from my small "runaway" camper trailer, and replaced them with these LED tail-lights. The LED lights are much brighter than the old lights. Installation was easy. Followed the instruction video. It took me about twenty minutes from start to finish. They work great and look great.

Still working great.
Bruce - 02/22/2019


I wanted submersible tail lights with the large hole on the bottom so the water would quickly drain out which was shown on your website. The lights arrived with the large hole on the top of the light with just a pinhole on the bottom which could quickly be clogged by debris allowing the light to freeze and break. After much discussion back and forth and sending pictures proving it was not as shown on your website, I finally got the charge removed from my credit card. In your defense I suspect that the manufacturer revised the product and did not advise you, or the manufacturer mislabeled the product. But I was surprised that I was charged for the return shipping. Lesson learned.


Installed the submersible Led trailer taillights on my unsprung motorcycle trailer. The 4 screws mounting the led/lens to the light housing vibrated loose and lost two of the screws. I made the mistake of trying a loctite thread block on the screws--- big mistake. Loctite crazes and cracked the plastic lens. Finally used silicon sealer adhesive to mount the entire lens/led lights to the brake light housing. All is well after 1 year of longer multi-state trips .


the lights and wires i ordered are what i ordered. they have not been installed yet as i am still modifying the trailer the are going to be instilled on. i believe that they will work just fine.


Lights are excellent! Replaced the completely non-functioning 38 cent lights they installed on the trailer at the factory with these. They are great, bright and very solidly functional.

No change. Lights are outstanding!!
Dennis - 10/28/2017


Ordered both left and right matching pair stl9rb and stl8rb , shipping was great came neatly packaged with plenty packing material and shipping cost was excellent in comparison to other sites .
The main reason for ordering was i am using an electronic wiring harness in 2011 Hundai Sonata,the standard tail lights on the trailer were incandandesent bulbs and pulled too much current kicking the breaker in the electronic control module on wiring harness , i was aware L.E.D.s draw much less current so when these plus marker lights were replaced .PROBLEM SOLVED , THANKS E-TRAILER


My trailer lights finally work with my Nissan pickup. After much trouble-shooting and with great support from the Etrailer tech. dept., I solved my turn signal/brake lighting problem. It turned out that it wasn't my ground or trailer wiring or defective trailer harness but that my pickup couldn't handle the extra amperes for the 1157 bulbs in the lights that came on the trailer. The Etrailer technician suggested getting LED tail lights which have a much lower amperes requirement than the 1157 bulbs. Now everything works. The lights were easy to install and are very bright. The Etrailer staff was fantastic. Thanks!


I purchased these lights to replace the factory lighting on my 10x6 utility trailer. The driver's side factory light had quit working and I decided I would like some better lighting. I installed them on my atv trailer which doesn't get used often but I will say these lights were easy to install and much brighter than my factory lights. I highly recommend them and enjoy shopping on etrailer.


Installed these vs the regular blub lights and these are much better. They are brighter and you don't have to worry about vibrating bulbs loose.

Have had them for a year and no issues. Would purchase again.
Mac - 11/27/2018


great value, excellent LUMENS, quick service,

jim a - 07/30/2021


Best replacement light I've found so far. Set out in the weather 24/7. Easy to install, fit brackets with no modifications.


Replaced original kayak trailer lights with left and right hand LED lights. Order arrived on time and I was able to track the shipment using the unique map tracking page. The installation was very easy using the helpful installation video available on the website. The lights worked the first tima and are twice as bright as the original. Definitely would order future products from!


Installed these on a lawnscaping trailer since the old ones had some corrosion. The original lights were similar and 13 years old. It sits outside mostly, so there shouldn't be any issues with these sealed units. Also used heat shrink butt connectors for the other 2 connectors. The ground had a ring terminal already on it. Also replaced the trailer wiring harness with the-
35 ft. Wishbone 4-Way Trailer Wiring Harness with 42" Ground Wire - A35W42B. All the electrical is brand new now!


Boat trailer light, well sealed, bright, color code even matched a yacht club trailer. If you don't care about the license plate light you can order two of the right lights and save a couple bucks although the color code may no longer match - no worries - you're smart enough to sort that. If your plate doesn't hang under the light the white lens on the bottom makes no difference


What a difference between led tail lights and incandescent bulbs. No more bulbs to dig out of carroded sockets no more loose no contact bulbs that will not light up. When the other tail light fails it is being replaced with an optronic led fixture. It is brighter and TROUBLE free.

Show More Reviews

Ask the Experts about this Optronics Trailer Lights

  • Does Optronics Replacement Side Marker Lens # AL9RB Use a Gasket
    The Optronics Replacement Side Marker Lens for STL8RB and STL9RB, part # AL9RB, does not use a gasket. This lens is used on the Optronics LED Submersible Trailer Lights, part # STL8RB, and part # STL9RB which does not require any gaskets because the LED light system is encased (sealed) in plastic making the LED light fixture itself waterproof. The side marker lens and the front tail light lens can be replaced if broken, but neither one requires a gasket since they do not need to be sealed.
    view full answer...
  • What are the Measurements of Optronics Replacement Side Marker Lens # AL9RB
    I went out to the warehouse and pulled the Optronics Replacement Side Marker Lens # AL9RB. It measures 2-13/16 inches across, 2-1/8 inches tall, and it is 3/16 of an inch thick. The mounting holes are 2-5/16 inches apart on center. The lens is for # STL8RB and # STL9RB lights which no longer use a gasket. The LED light system is encased (sealed) in plastic making the LED light fixture itself waterproof.
    view full answer...
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  • Do LED Trailer Lights Have Replacement Parts?
    The Trailer Tail Light # STL8RB, which is the passenger's side light, as well as driver's side # STL9RB, have have just the replacement lens available, part # AL9RB. I can genuinely say there are no problems commonly associated with these lights; if you check out the "Reviews" section on the product page you can see that with over 250 reviews, these lights have gotten a nearly 5-star rating so as long as the lights are properly grounded there are not going to be any issues whatsoever.
    view full answer...
  • Lights on 1999 Magic Trail Trailer By Magic Tilt Do Not Work
    SAE is correct, it stands for Society of Automotive Engineers. The SAE followed by numbers and letters is a lens rating. LED lights are usually sealed or the LED module itself will be sealed. They can burn out but it would either take a long time or an event such as a bad short to cause them to burn out. You might actually have 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...
    view full answer...
  • Left Side Boat Trailer Tail Light Does Not Have Power when Bulb is Installed
    The most likely problem is going to be a bad ground. Without the bulb in, there is no draw on that light and ground issues normally show up when there is a load on the system. If you recently install a plastic license plate holder in between the light housing and the trailer frame, that can cause this problem (if the lights ground through the mounting studs). The solution will be to run jumper grounds (no matter how the lights ground to the frame) to the main trailer connector ground....
    view full answer...
  • Can Trailer Tail Lights Be Mounted Upside Down So License Plate Can Be Above Lights
    The Optronics LED Trailer Tail Light # STL9RB can be mounted however you would like. So there's nothing that will prevent the light from working. However, I would suggest checking with the DOT in your area to make sure that there aren't any laws against it.
    view full answer...
  • What are the Functions of the Wires of a Trailer Taillight that Has Red, White and Black Wires
    For trailer taillights that have the three wire colors you mentioned the white wire is the ground, the black is the taillight and the red is the turn signal/brake light.
    view full answer...
  • Replacement LED Light Installation on Trailer Cargo Platform
    If you intend to wire your new additional lights into the existing lighting circuits on your trailer then I do recommend using LEDs since they will add a minimal additional power draw on that wiring. Since you probably have no way to know for sure about the power-handling capacity of that internal trailer wiring using high-efficiency LEDs lights is the safer way to go. It is okay to mix incandescent and LED lights but note that they typically have different brightness levels; LEDs usually...
    view full answer...
  • Troubleshooting Trailer Wiring that Stops Working When Headlights Are On
    Try improving the connection of the main ground wire of the trailer wiring harness. Make sure it is attached to a clean metal surface. Or you can run all of the trailer wires back to the main ground. This is actually the ideal solution. But you can also check the current grounds for the lights to make sure they are making a solid connection to a clean metal surface. What you described is the classic insufficient ground scenario so finding a way to improve the grounds will fix the problem.
    view full answer...
  • Troubleshooting Trailer Lights not Working with 2009 Honda Pilot
    This is an issue we run in to quite commonly when installing Combination LED Trailer Tail Light part # STL9RB or any other trailer light. The good news it has nothing to do with the vehicle 99% of the time. The most common cause for this is bad grounding at your lights or at the wiring harness ground. When this came into the shop my first step would be to remove sand down to good steel and replace each ground. That will likely solve your issue. The very dim light coming through is an indication...
    view full answer...
  • What is the Function of the White Wire on LED Trailer Tail Light # STL8RB
    The white wire on the LED trailer tail light # STL8RB is the ground wire. It will need to attach to a clean and corrosion free bare metal surface. I have included a link to a video review of this light for you. The matching left side tail light is # STL9RB.
    view full answer...
  • Solution for Trailer Taillights That Short Out When Backed into Water
    The LED Submersible Trailer Stop, Turn and Tail Light # STL8RB that you referenced is submersible so it would work well for you. However, the solution that most use to avoid the problem you are having is to unplug your trailer connector before you back your trailer into the water as electricity and water do not mix well. I would not recommend plugging the trailer back in till the trailer has been out of the water for several minutes. I imagine that most of the times that your lights burn...
    view full answer...
  • Can a Passenger Side Tail Light Be Used on the Driver Side of a Trailer
    Left side tail lights have a clear lens on the bottom to light up the license plate. Right hand side tail lights do not. If you were to use the right hand side light, # STL8RB, you would need a separate light to illuminate the license plate. The left hand side light that matches is # STL9RB. If you click on the last picture on the product page, you will see the lens.
    view full answer...
  • What are the Wiring Colors and Functions for the Optronics LED Trailer Tail Light # STL9RB
    On the LED tail light # STL9RB, the yellow wire is for turn/brake lights, the brown wire is for running lights, and the white wire is the ground. The license plate light will illuminate with the running lights. The matching right hand side is # STL8RB.
    view full answer...
  • Why is the Left Hand Light More Expensive than the Right Hand Light?
    The left hand taillight is more expensive because it contains more LED lights than the right side, due to the addition of the license plate light on the bottom of the light. The white LED is more expensive to produce also and that adds to the cost of the left hand light because the license plate lamps are white.
    view full answer...
  • Are Parts # STL9RB and # STL8RB the Same but Opposite Tail Lights
    Yes these are the right and left hand side lights. Because of the side marker light on the side of the lamp, Part # STL8RB should only be used for the right hand tail light. The left LED taillight would be part # STL9RB. For install details and some product demonstration videos, click the provided links.
    view full answer...
  • Quantity of Lamps Included with Optronics LED Trailer Taillght STL8RB
    The Optronics Trailer Taillight # STL8RB is the passenger side taillight only. The driver's side taillight is sold separately as part # STL9RB. If you click the provided link, you can see a video showing these lamps being installed.
    view full answer...
  • Matching Optronics Driver-Side LED Trailer Light to Match STL8RB
    The matching driver-side LED trailer light that goes with part # STL8RB is their part # STL9RB. This driver-side light also has a license plate light (its 7th function). Both lights mount using the studs on the rear of the housing and it uses a 3-wire hookup: white wire is the ground; brown wire is for the tail lights; and yellow wire is for the stop and turn lights.
    view full answer...
  • Replacement STL8RB Tail Lights for Utility Trailer
    For your utility trailer, I recommend the Optronics Trailer Tail Light # STL8RB for the Passenger Side and # STL9RB for the Driver Side. These are direct replacements for your existing lights and will work perfectly on your trailer. These assemblies are 5-1/16 inches long and 4-9/16 inches wide. I have attached an installation video on these tail lights that you can also take a look at.
    view full answer...
  • Why Does the Optronics Driver Side Tail Light STL9RB Have More Diodes Than the Passenger Side STL8RB
    The reason that the Passenger Trailer Tail Light # STL8RB has 11 diodes and the Drivers Side # STL9RB has 14 diodes is because the driver side light has an additional function; license plate illuminator. This is why you see a difference in the amount of diodes. I have attached a picture of the underside of the driver side light so you can see the license plate illuminator. I have attached some review videos as well as an installation video for you to check out.
    view full answer...
    Image 1 for
  • Recommendation For Matching Driver And Passenger LED Trailer Tail Lights
    The driver side tail light that matches Item # STL8RB is Item # STL9RB. This trailer light is the same as # STL8RB but has additional functions related to the driver's side. It has the added function of license plate light. Additional information and videos attached.
    view full answer...
  • Matched Pair of Optronics LED 7-Function Trailer Tail Lights
    You can use Optronics Trailer Tail Light # STL9RB as the match for the passenger-side light # STL8RB. These high-efficiency LED lights will provide both brighter output and reduced power demand as compared to standard incandescent lights. Both are stud-mount lights that use a 3-wire design.
    view full answer...
  • Is Replacing Trailer Taillights with LED part # STL8RB an Easy Swap
    The trailer taillight style of the part # STL8RB is very common. Probably the most common on the road today. If you wanted to swap out your lights to these that are LED it would be a very simple swap. All you'd need to do is wire up the new assemblies like your old ones and then bolt these in place. For the matching driver side you would want the part # STL9RB.
    view full answer...
  • Replacement 5 inch Trailer Light
    Some of our most popular 5 inch x 5 inch trailer tail lights come from Optronics and can be found with part # STL9RB for the Driver Side or part # STL28RB for the Passenger Side. These are submersible 18 Diode LED Square Lights. If these are not the correct style or fit I have also attached a link to our selection of trailer lights for you to filter through.
    view full answer...

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