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Tail Light for Trailers Over 80" Wide - 8 Function - Incandescent - Square - Driver Side

Tail Light for Trailers Over 80" Wide - 8 Function - Incandescent - Square - Driver Side

Item # ST3RB
Our Price: $14.51
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Shipping Weight: 0.58 lbs
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6-1/8" x 4-9/16". Incandescent light acts as brake, tail, turn, side marker, side reflector, rear clearance, rear reflector, and license plate light for trailers wider than 80". Stud mount. Quick connect wiring. 2 bulbs. Great Prices for the best trailer lights from Optronics. Tail Light for Trailers Over 80" Wide - 8 Function - Incandescent - Square - Driver Side part number ST3RB can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (83)
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  • Videos (2)
  • Photos

Optronics Trailer Lights - ST3RB

  • Tail Lights
  • Square
  • Incandescent Light
  • Red
  • 6-1/8L x 4-9/16W Inch
  • Surface Mount
  • License Plate
  • Rear Clearance
  • Rear Reflector
  • Side Marker
  • Side Reflector
  • Stop/Turn/Tail
  • Non-Submersible Lights
  • Optronics

6-1/8" x 4-9/16". Incandescent light acts as brake, tail, turn, side marker, side reflector, rear clearance, rear reflector, and license plate light for trailers wider than 80". Stud mount. Quick connect wiring. 2 bulbs.


  • Square trailer light serves 8 functions for trailers more than 80" wide
    • Stop, Turn, Tail, Rear Clearance, Rear Reflex, Side Marker, and Side Reflex
    • Built-in license plate light illuminates trailer license plate
  • Built-in reflector removes the need for a separate reflector
  • Incandescent bulbs are easy to replace
  • Shock-proof socket protects bulbs against damage
  • Durable plastic housing with screw-on lens
  • Red lens covers incandescent bulbs
  • Compatible with 12V DC systems
  • Stud mount to trailer with included studs
  • Quick connect wiring - simply insert stripped wire into holes for a secure connection
    • Light grounds through mounting studs
  • DOT compliant


  • Configuration: driver side
    • Passenger side: ST2RB (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"
  • Bulb type; 1157
  • Number of bulbs: 2
  • Power draw at 12.8V:
    • Stop/turn: 2.5 amps
    • Tail: 1.0 amps
  • 3-Year warranty

Manufacturer Cross Reference
Light will work as an exact replacement for:
Uni Bond # TL4440L
Wesbar # 423012
Peterson # M444L

Optronics ST3 Series Universal Tail Light Dimensions

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.

ST3RB Optronics Combination Tail Light for Trailers Over 80" Wide - 8 Function - Incandescent - Square - Driver Side - Left Hand

Alternate part number: ST-3RB

California residents: click here

Video of Tail Light for Trailers Over 80" Wide - 8 Function - Incandescent - Square - Driver Side

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

Video Transcript for Optronics Tail Light for Trailers Over 80 inches Wide Review and Installation

Randy: Hey guys, Randy here at So we're going to be taking a look at an incandescent square light from Optronics. Now, these are designed and suited for use on just about any type of trailer, but they do meet the DOT compliance factors for trailers over 80 inches wide. I think these are going to be very good on most of your utility trailers and things like that, out there. Since it is incandescent and not submersible, I don't think it's going to be ideal for boat trailers and things like that. But outside of that, if you've got a square type light, it's going to use the standard two-inch bolt pattern or two-inch studs in the back, and it should just be a direct replacement, especially with the push to connect that we have on the back, just strip off your wires and plug them into the appropriate hole and the light's going to work well for you.Now, driver and passenger side are going to be a little bit different.

Our driver's side is going to have a lens here on the bottom. That's going to light up and it's going to help to illuminate our license plate, which is required in most States. The only difference between this and the passenger side is that it's not going to have that one. Now with incandescent lights, they do tend to be a little bit more fragile than what we see out of LEDs. If I had the option and if I had the choice, if I we're replacing lights on my trailer, I would go with a LED option.

They tend to be brighter, they use less power and they last a lot longer. However, there are always places for incandescent lights and where they can be used, especially if you're just going to be replacing one and you've already got an incandescent on the other side, will look a little weird if you mix them up, so I'd either replace it with a single incandescent or if you want to refresh it, switch them both out for a LED type.Now the housing is really nice and sturdy. Not a lot of flexing give to it, and our lenses are going to be acrylic. They should last for a very long time without any real discoloration or anything like that. And unless you run into these as something pretty significant or really drop a brick on them or something like that, I really don't think you're going to have any issues with breaking or cracking.

Now, while I think these are good lights, I think they're going to do the job and I think they'll do it for a long time for you. I've hauled a lot of trailers in my day and one of the number one headaches is you get somewhere, you hook up to the trailer and the lights aren't working, and maybe it's just a bad ground or something, but more often than that, I've found that the bulbs busted or the socket where the bulb fits into has corroded.Now this does use a shock proof socket to help maintain that filament and the incandescent bolt and keep it from breaking. But, I strongly recommend if you're going to go this route that you use some dielectric grease at that connection point. It's going to help to reduce the moisture, getting on there, causing corrosion, which usually causes issues. Now with those push-to-connect fittings, we talked about, it's very important that we get our wires very tightly wound.

So I like to spread them out a little bit and then wrap them. It's going to give us a good stiffness. If we just left him kind of all single strands, really not going to be able to get them in there, all that well, and at that point, we're going to take our brown wire or whatever wire is giving you your tail light signal. It's going to slide into the tail light, opening here, push it in all the way, just like that.The other side, we'll use our yellow wire for the stop and turn or whatever color your stop and turn signals come from, just like that. And you see right here, you get the area for that wire to sit down in it, at that point, let's take off our flans nuts here and get it mounted to the trailer. Put that through our mounting holes, which are on two inch centers, get that secured down. Then we'll use our seven sixteenths and tighten them up.I like to take my excess, which I always leave a little bit of, just in case we ever have any issues anywhere, we've got some extra wire to use, so tie that. Then we'll zip tie it up to the trailer. Once you get this nice and secure, it's just time to head over to your passenger side, do the same thing there. The only difference is going to be your wire. It's going to be your right turn and brake rather than your left turn and brake, and that's generally green. Now we can test them out and make sure they're going to work properly. It's going to turn on our tester here. You could also simply plug these into your towed vehicle. It's like the tail lights are working good. We can do our left turn signal, do our right turn signal and our brakes. Looks like everything here is working as it should..

Customer Satisfaction Score:

Customer Reviews

Tail Light for Trailers Over 80" Wide - 8 Function - Incandescent - Square - Driver Side - ST3RB

Average Customer Rating:  4.8 out of 5 stars   (83 Customer Reviews)

6-1/8" x 4-9/16". Incandescent light acts as brake, tail, turn, side marker, side reflector, rear clearance, rear reflector, and license plate light for trailers wider than 80". Stud mount. Quick connect wiring. 2 bulbs.


Quality of the light is good. Installation on my trailer would have been easier if it had been possible to order a light with pigtail wires included so I could have directly connected to my trailer wiring. I worked around it by adding my own pigtails.


Great replacements. Work as you would expect a set of lights to work. I usually have to replace one or both lights and the connector when borrowing a friend's trailers because his son trashes them every time he uses one. Small price to pay for unlimited use of a trailer and my friend gest his trailer repaired at no cost to him.


The trailer light arrived quickly and as advertised. The shipping charge was very minimal (less than $3). The studs to connect the light to the trailer had two different nuts, but I figure they were bonus hardware since they matched the types on the old light I was replacing. The picture I included is of the broken light this one replaced.


I am always satisfied with the products I buy from etrailer. The taillight I ordered was just as advertised. I appreciate the fact that I was asked to rate the product/service a year after purchase. So many times I order something and the sender is wanting me to rate it before I have a chance to use it. I have been using the taillight for a year now and it works perfectly. Good product, good service.


good cheap replacement for the lights on my utility trailer ... seems like I'm breaking them on a regular basis when I use the trailer on my property to haul materials, firewood, etc.


This is my second purchase from etrailer. Great service, great selection! site is easy to navigate. Will buy all my trailer needs from etrailer!

Kevin H.


Good morning! All good! Wow Etrailer does a fantastic job. The lights are working well. I appreciate your customer service. Second to none!


Broke the tail light on my utility trailer by catching the tail light on a fence post pulling into my back yard. Ordered these tail lights as they are an exact replacment . This light was exactly as advertised and fit perfectly which made replacing only take a few minutes. This was my first purchase from and I'm very pleased with the service and product . I will be using for my future trailler part needs as I have 3 trailers to maintain .


Got too close to a post and managed to crush a tail light on my trailer. Found E-trailer and took a chance. The tail light was easy to find on their website and ordering was a snap. Delivery was right in the middle of the timeframe they stated which was surprisingly fast... especially when I live in the middle of nowhere. Thanks e-trailer


A virtually identical product to the trailer lights on my 2009 TrailerTex 20 footer. The originals corroded after 8 years. I guess if these new ones last that long there is value in the purchase. It is not possible to connect the wiring without first soldering the ends of your wires given the "push through" anchors of the fixture.


Etrailer provides a user friendly web page, excellent service, reasonable pricing, fast delivery, and follow up service to ensure customer satisfaction. I recommend highly.


Ordered 2 tail lights for my small trailer. (1 left side and 1 right side) Excellent web site and items were well described. VERY VERY fast delivery. I watched several available videos that were on the order page and found them to be very helpful with the installation. Thanks to I will be back on the road again. I will let my friends know about the great service and products.


I purchased these tail lights to replace the ones that my father had broken on our trailer. He broke them several years ago and did not replace them because he he thought that they would be too expensive. I found these on the etrailer website. I was surprised at how inexpensive they were. At this price, they should have been replaced years ago. They are exactly like the original ones that came on the trailer (same brand/same size). Since they were identical to the original ones, the installation was a breeze.


Great product for the price. One issue to note...the mounting studs should be 1/2" longer in order to accept the license plate mount.


Good product selections and prices. Fast, fast, shipping.



Works just fine. Durable!


I ordered this tail light after smashing mine on my fence while backing up my trailer. I was surprised at the great pricing and delivery was super prompt. I ordered two since this fence is likely going to jump out at me again in the future.

Thanks for the great product and service!!!


Bought this for my new dump trailer, light was broken after first load so needed a replacement! This was an exact replacement and works great and the price was the best I found.


It was an exact replacement for the lights on my utility trailer. It shipped on time and was packaged nicely in secure packing.


I’ve been using etrailer for several years and found the products great and very reasonably priced. I rarely buy and trailer parts locally.


Exactly what I ordered. Came quickly. Good price. Works great. Easy install. Very convenient. Would order again.


Delivered as expected. Product was as described. Will purchase from etrailer again in the future.


Replacement of a broken taillight for trailer. Perfect match.


Item was received very quickly and was as described on the etrailer website. Great Service!


Great product. Exact replacement fixture I was looking for to place on my trailer. Thanks.


Perfect match to trailer, easy installation and received in mail quickly.


Great service, fast shipping and a good price! I'm very happy w/ r etrailer and would use them again! ??

Show More Reviews

See what our Experts say about this Optronics Trailer Lights

  • Replacement Side Red Lens for Peterson 440-15 Trailer Tail Lights
    Does the side lens on your Peterson 440 lights mount with screws or is it held on with clips and doesn't have screw holes? You could potentially use # 55-15R as long as the lenses you have also use mounting screws or have the holes in the base for screws.
    view full answer...
  • Replacement Tail Light with License Plate Light Lens Integrated
    The side marker light lens like # 56-15R you referenced normally does not have the clear license plate lens attached. We do not have any lenses like that. We do however have the Over 80" Wide, Square Trailer Tail Light with License Plate Light, 8-Function, Left Hand # ST3RB which has a side marker like that but has the license plate lens on the bottom of the tail light assembly. Another option is to run a separate license plate light like # PM436B.
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Info for this part was:

Employee Michael H
Expert Research:
Michael H
Employee Adele M
Updated by:
Adele M
Employee Laura H
Updated by:
Laura H
Employee Brian T
Updated by:
Brian T
Employee Dustin K
Video Edited:
Dustin K
Employee Cole B
Installed by:
Cole B
Employee Randy B
Installed by:
Randy B
Employee Zach D
Video by:
Zach D

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