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Optronics Transit Light - Stop, Tail - Incandescent - Round - Red Lens

Optronics Transit Light - Stop, Tail - Incandescent - Round - Red Lens

Item # ST90RB
Our Price: $26.51
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Shipping Weight: 0.99 lbs
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7-1/8" Diameter incandescent transit light acts as a brake and tail light. Durable steel housing. Screw-on lens. Surface mount - hardware not included. 2-Wire design. Great Prices for the best trailer lights from Optronics. Optronics Transit Light - Stop, Tail - Incandescent - Round - Red Lens part number ST90RB can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (233)
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Optronics Trailer Lights - ST90RB

  • Tail Lights
  • Round
  • Incandescent Light
  • Red
  • 7-1/8 Inch Diameter
  • Surface Mount
  • Stop
  • Turn
  • Non-Submersible Lights
  • Optronics

7-1/8" Diameter incandescent transit light acts as a brake and tail light. Durable steel housing. Screw-on lens. Surface mount - hardware not included. 2-Wire design.


  • Round trailer transit light serves 2 function
    • Stop and tail
  • Incandescent bulb is easy to replace
  • Durable steel housing
  • Red screw-on lens
  • Compatible with 12V DC systems
  • Surface mount - hardware not included
    • Included foam gasket helps create a weathertight seal
  • 2-Wire design includes power lead and ground wire


  • Dimensions: 7-1/8" diameter x 2-3/16" thick
  • Distance between mounting holes (center on center): 6-1/4"
  • Bulb type: 1157
  • Power draw at 12.8V:
    • Stop: 2.4 amps
    • Tail: 0.5 amps
  • 3-Year warranty

dimensions of light

ST90RB Optronics Transit Light - Stop, Tail - Incandescent - Round - Red Lens

Alternate part number: ST-90RB

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Optronics Transit Light - Stop, Tail - Incandescent - Round - Red Lens - ST90RB

Average Customer Rating:  4.9 out of 5 stars   (233 Customer Reviews)

7-1/8" Diameter incandescent transit light acts as a brake and tail light. Durable steel housing. Screw-on lens. Surface mount - hardware not included. 2-Wire design.


I installed these lights on my vintage 1964 Holiday Rambler, and was very happy with the final outcome. They wired into the existing electrical system, and were the exact same size as the original faded lights they replaced. Couldn't find replacement lenses for the original lights, so these were the next best thing. And they worked perfectly.



I still own the coach and they are performing well. Thank you.


I installed these when I restored my 1969 Gold Star travel trailer. They installed easily and there was no issue grounding them to the aluminum skin. They illuminate well at night.


I bought 4 of these to replace the old non-working taillights on my 1967 Holiday Rambler camper. They were easy to install and were the exact same size as the old lights.



Ive had these on my camper for a year now, and they still look and function like the day I got them. Since that time, I have painted the camper and replaced all of the marker lights. those were also purchased from etrailer. Installed new tires and wheels, and tongue jack. The camper looks like its brand new. Im glad I found etrailer. They have saved me a fortune restoring this old thing. I would love to add new pictures of my camper, but I dont see any option to do that.


a year in and are doing ok. bulb holder is slightly temperamental on bulb placement. once a good connection is made it stays good, but you may think you have bulb inserted correctly, but test before placing lens cover on. bulb may require small adjustment.


About the only replacement for an Autolamp 575. Mounting holes line up perfectly, but the foam gasket is not great for vintage use. I removed it and used putty tape. I also opened the lamp to find it had a ground connection that had been cut...very lame. I ended up adding my own internal ground wire to make sure I had a good ground rather than the marginal ground through the mounting screws.


Hi have been working on my 1964 Holiday Rambler project and was looking to replace the old 7 inch round tail lights,they where cracked and faded and had bad bulb sockets. I found these new 7 inch tail lights at and they are a grate looking replacement EZ install and a good price,shipping was fast always a plus in my book, Vary happy with my purchase. TY :)


I needed 2-7" round tailights to match the broken ones on my 1968 Serro Scotty camper. These were way better than I was thinking. Very fast shipping. Thanks, I am just about to head out on the highway!


We really like the new tail lights. We initially wanted the original vintage look ones but they were not easy to find and the couple we did find were very expensive. We ordered these instead and love how they look! Great choice and they arrived super quick!


Quick ordering and delivery process


Perfect replacement lights for our vintage Shasta!


I love the school bus tail lights. Replaced the wedding cake tail lights on a 1963 Traveleeze trailer.


Very happy with the service and the parts were a perfect fit--1965 Corsair 18' camper


Nice product, great price. Much heavier molded plastic than I thought they would be. Purchased for my 1967 Pathfinder Camper. Same 7" diameter as original cake light. Great fit!


Great product. Used on 1965 Beeline Camper.

Thomas M.


Product still looks and works great


I just received a pair of 7" round taillights for my 1969 Aristocrat 16 footer. The old ones were broken and had rusty connections.
I am so pleased with my new ones from eTrailer. Not only were they priced fairly and shipped expediently, but looked great ! A very good sealing system and easy to rewire. Thanks etrailer for a great product !



Perfect. Could not ask for a better product.


Just received the replacement lights and they are as advertised. I needed the large size to cover the 6 1/2" original lights mounting holes. I have not installed them yet, but they seem to be reasonably well made, unfortunately there is no clear lens on one for license plate illumination (I did know that prior to ordering them.) I think that they are a good buy and I would buy them again if needed.



I purchased these lights for my 1966 canned ham to cover the openings from the old tail lights. They’re good quality and they work just fine. If I ever had to replace them I would purchase the same items.


I'm very pleased with the trailer lights I just received from etrailer; they are even nicer and more substantial than I had expected. Service was friendly, the order was accurately filled, and delivery was prompt. I will definitely buy from etrailer again.



Better than I could have hoped for. The old lights on my travel trailer were dim and sometimes didnt work at all. The new ones are bright and always work. No more worries about being rear-ended.


Awesome that they have the vintage look, exactly what I was looking for.


Just what I was looking for, love them on my vintage camper.


These lights were just what I needed to finish my 1965 Fan camper ,they look and work great.


i ordered after mkt, 7 inch round tail lights for my vintage 68 kencraft trailer. . . very high quality . . .these will be my go tothey look great etchad to mount my own ground wire as theyre being mounted on fiberglass. . .not a problem this company has a vast selection of cool stuff & my lights arrived very quickly these will be my go to guys. . .


These light fixtures are simple and fit on the trailer well. The wires are long enough to actually use. I put LED bulbs in them and this is very bright. Good product. Good price.


The light look and work great ! The size and design is so close to the original 1968 ones that you cannot tell the difference except for the lack of a clear lens area on the bottom for the license plate .
All in all, You have fantastic product and a very fair price. My 1968 Aristocrat Land Commander thanks you very much !


These lights work great for replacements of vintage trailers. They are the same size, and I think they look better.

Dan C.


Still, great replacement for vintage trailers.


Perfectly replaced the light assemblies on my '67 Holiday Trav'ler travel trailer. Easy installation and they are bright, even during the day. Note: the original lights grounded to the body, these lights have to be grounded to the frame. I've recommended them to many Holiday Traveler vintage trailer owners. They really do look nice!

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See what our Experts say about this Optronics Trailer Lights

  • Diameter of Lens A90RB
    The lens diameter of part # A90RB is 7-1/8 inches. It is meant to fit part # ST90RB lights.
    view full answer...
  • Does Optronics Tail Light Lens A90RB Include a Clear Portion for a License Plate Light
    This lens is meant to be used as a replacement to the Optronics tail light, part # ST90RB. It does not have a clear portion for a license plate light. You are looking for a light like Optronics part # ST9RB or part # STL9RB. You could also use Optronics part # ST17RB. I have linked to these parts below.
    view full answer...
  • How To Wire Two Optronics Transit Lights ST90RB With One Being Stop/Turn and One Being Running
    The Optronics Transit Light part # ST90RB is a multi function light designed to work with the stop/turn signals and running light signals. If you had a pair on each side and wanted the outside lights to be the stop/turn and the inside to be running simply hook up the stop/turn light wire (usually yellow/green) to the red wire on the outside light and leave the black one capped off. Then for the inside light, attach the running light wire (usually brown) to the black wire and leave the red...
    view full answer...
  • Will Optronics Trailer Light # ST90RB Light Up if Connected Directly to a 12 Volt Battery
    I can honestly say I have never had someone building a railroad crossbuck sign ask me a question! But, yes, the Optronics light # ST90RB will illuminate steady when connected to a 12 volt power source, like a battery, provided that the power source has a charge (if the battery runs low the light can dim). An LED light, like # STL90RB, will be brighter and use less power. It would not look as authentic, but it will consume less power and last longer. To be able to turn the light off and...
    view full answer...
  • Installing Optronics Round Transit Stop and Tail Light On 1965 Chief Little Arrow Camper
    I am glad to hear this light will work for your vintage camper. Since there are many ways these lights can be mounted it would be really difficult to include the mounting hardware. I recommend checking out the hardware you have that your current lights are attached with and visiting a local hardware store to get the new hardware to attach the # ST90RB lights. The red wire is attached to the brake/turn signal wire and the black wire is attached to your running light wire. Since the light...
    view full answer...
  • No Running Lights Using Round Transit Stop and Tail Light - Red
    Optronics tail light # ST90RB is unique in that it is designed as a brake light and tail light whereas most trailer lights are brake/turn and taillights. But it can function as a brake/turn/taillight when the red wire is connected to the combined brake/turn signal wire on the trailer and the black wire is connected to the trailer running light wire. This light grounds through its mounting hardware. If the trailer has an aluminum frame, tilt bed, or folding tongue then running jumper wires...
    view full answer...
  • Mounting Optronics Transit Light
    The mounting hardware for the Optronics Transit Light # ST90RB does need to be locally sourced at a hardware store as it is not something we (or the manufacturer) has a available. I recommend just bringing the light along to the store with you to find the right hardware so you can mount it without issue.
    view full answer...
  • Front Lights on Trailer Work But Rear Lights Dont Work and Get Hot
    That definitely sounds like a ground issue. If your wires are hot and you are getting signals to the lights in front of them then you need to check your grounds. Not only do you have a main ground wire but each light itself will have a ground. Check to make sure that your grounds are secure and connected to a clean, bare-metal surface. If those look good then the only other thing would be some damaged wiring. Check from the working lights to the lights that don't work and look for any...
    view full answer...
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  • How Many ST-90RB Lights Come With One Part Number Order?
    The 7" Round Transit Stop and Tail Light - Red # ST90RB come individually. You would need to order 2 for a matching pair.
    view full answer...
  • Does 7 Inch Round Transit Light, # ST90RB, Have Brake, Turn, and Tail Light Functions
    The 7 Inch Round Transit Light, # ST90RB, is a 2-function light. This round red transit light is used as a stop and tail light when connected to combined stop/turn circuit. For stop, tail, and turn lights, you will need a 3-function light like # ST24RB.
    view full answer...
  • How Many Lights Are Included with Optronics 7 Inch Round Transit Stop and Tail Light # ST90RB
    The Optronics 7 Inch Round Transit Stop and Tail Light # ST90RB referenced in your question includes one light assembly. They are not available in a set, so you will just need to order two. This is a really nice, round tail light that measures 7-1/8 inches in diameter and has a depth of 2-3/16 inches. The gasket is included to create the weathertight seal and the light will ground through its mounting hardware. I have attached a short video demonstration on this light that you can also...
    view full answer...
  • Troubleshooting New Trailer Tail Lights Turning Off When Bumped
    If the Optronics 7" Round Stop and Tail Lights # ST90RB that you recently installed on your trailer are turning off and on when touched then this likely indicates a weak connection somewhere on the assembly, either with the power wires or the actual mounting hardware. First make sure both the black (tail light) and red (stop light) wires are securely connected to the trailer wiring. If the wiring looks good then you can turn your attention to the mounting hardware/screws. This particular...
    view full answer...
  • How Many Functions Can the 7 inch Round Transit Stop and Tail Light # ST90RB Do
    This 7 inch Round Transit Stop and Tail Light # ST90RB can do stop and turn signals when used on a combined stop/turn circuit, but it cannot do taillight functions as well. The closest thing to a 7 inch 3 function trailer light we have is the 4-3/8 inch Round Trailer Tail Light, Stud Mount, 3-Function Trailer Light # ST24RB. However, this light is only 4-3/8 inches in diameter.
    view full answer...
  • Replacement Taillight Options for 1967 Airstream Caravel Trailer
    I have a solution for you, but we do not offer any vintage 575 lights. I was able to find that the 575 lights were round taillights that measured 7 inches in diameter. To replace your exisiting lights with those of the same diameter, we offer both incandescent and LED lights. Our most popular 7 inch diameter, round, red trailer taillight is the Optronics # ST90RB. This is an incandescent, sealed taillight. The three taillight options that come with LED lights are the Optronics # STL90RB,...
    view full answer...
  • Will the Optronics Round Transit Stop and Tail Light A90RB Fit a Weldon 1010 Taillight
    The Replacement Tail Light Lens for Round Transit Stop and Tail Light part # A90RB is designed for the Optronics Transit Light part # ST90RB therefore I cannot confirm it will work on your Weldon 1010 Taillight. They do have the same diameter so it may work in its place but otherwise you would have to replace the entire light assembly in which case this will be your best option for this.
    view full answer...
  • Replacement Rear Stop/Turn/Tail/License Plate Combo Cake Light for 1968 Pathfinder Travel Trailer
    Thank you for providing the photo of the 7-inch combination Stop/Turn/Tail/License Plate Combo Cake Light from your 1968 Pathfinder travel trailer. I was able to find photos and some comments on trailer owner forums regarding your 1968 Pathfinder trailer, but not any specific information regarding the manufacturer of the original light fixtures. Given the age of this venerable old trailer it is quite possible that the original manufacturer of the cake light is no longer in existence....
    view full answer...
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Info for this part was:

Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Adele M
Updated by:
Adele M
Employee Laura H
Updated by:
Laura H
Employee Brian T
Updated by:
Brian T
Employee Cole B
Installed by:
Cole B

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