bing tracking image
  1. Trailer Lights
  2. Optronics
  3. Clearance Lights
  4. Rectangle
  5. Incandescent Light
  6. Red
Square Trailer Clearance, Side Marker Light with Reflector - Red
Optronics

Square Trailer Clearance, Side Marker Light with Reflector - Red

Part Number: MC36RB
In Stock
$6.04
Retail:$6.55
You Save: 8%
Trailer Lights
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.
By submitting this form, you understand and agree to our Terms of Sale, Website Terms of Use and Privacy Policy.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

2-3/4" L x 2-1/8" W x 1" D; Reflectorized lens; corrosion resistant; replaceable lens and bulb; mount on stud; 1-wire; 1-bulb incandescent Great Prices for the best trailer lights from Optronics. Square Trailer Clearance, Side Marker Light with Reflector - Red part number MC36RB can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
  • All Info
  • Reviews (4126)
  • Q & A (0)
  • Videos (1)
  • Photos

Optronics Trailer Lights - MC36RB

Highlights

  • Two Lights in One: Works as both a clearance and side marker light for added visibility.
  • No Extra Reflector Needed: Reflectorized red lens meets DOT requirements on its own.
  • Built to Last: Molded plastic housing and lens resist weather and corrosion.
  • Easy Maintenance: Replaceable lens and bulb make service quick and low-cost.
  • Simple Hookup: Single 18-gauge wire powers the light; grounds through mounting stud.
  • Compact Fit: Measures 2-3/4" L x 2-1/8" W x 1" D for tight mounting spaces.

Features to know about

Reliable Visibility in a Compact Package: 2-3/4" x 2-1/8" Red Marker Light

This square clearance and side marker light keeps things simple and effective. At just 2-3/4" long, 2-1/8" wide, and 1" deep, it fits neatly on most trailer surfaces without taking up extra space. The red lens is reflectorized, so you don’t need a separate reflector for DOT compliance. It functions as both a clearance and side marker light, giving your trailer consistent visibility in a small, sturdy form factor.

Built to Last: Corrosion-Resistant Design with Replaceable Parts

The molded plastic housing and durable lens guard against corrosion and weathering, keeping it dependable in the long run. When maintenance is needed, both the lens and the single incandescent bulb are replaceable—no need to toss the whole unit. That simple design makes it easy to keep your lighting system working like new.

Straightforward Wiring: Single-Wire Installation with Stud Ground

Wiring doesn’t get much easier than this. The light uses an 18-gauge single lead wire for power and grounds directly through its mounting stud. That means fewer connections to worry about and a clean look once it’s mounted. It’s a simple, proven setup that just works.

DOT-Compliant Safety Without the Extras: Built-In Reflectorized Lens

Safety lighting shouldn’t require extra parts. This light’s built-in reflectorized lens meets DOT requirements on its own, eliminating the need for a separate reflector. It’s an efficient way to stay compliant while keeping your trailer lighting clean and functional.

Specs

Dimensions

  • Length: 2-3/4"
  • Width: 2-1/8"
  • Depth: 1"

Technical diagram showing dimensions and structure of Optronics square red trailer clearance and side marker light with reflector, model MC36RB, measuring 2-3/4 by 2-1/8 by 1 inch.


Construction and Design

  • Shape: Square
  • Lens: Reflectorized red lens (eliminates need for separate reflector)
  • Housing Material: Molded plastic
  • Lens Type: Durable and replaceable screw-down lens
  • Bulb Type: Replaceable incandescent bulb
  • Mounting Method: Stud mount
  • Grounding Method: Single-wire design (grounds through mounting stud)
  • Corrosion Resistance: Weather and corrosion resistant

Manufacturer Cross Reference

  • Uni Bond #: MR2020R
  • Wesbar #: 3103
  • Peterson #: 114R

MC36RB Red Square Reflector Marker, Clearance Light by Optronics, Inc.

Alternate part number: MC-36RB





Video of Square Trailer Clearance, Side Marker Light with Reflector - Red
Video Thumbnail Video Player Dialog

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




Video Transcript for Feature Breakdown: Square Trailer Clearance, Side Marker Light with Reflector

Hello everybody, this is Jeff at etrailer.com. Today, we're gonna take a look at this Optronics Red Square Trailer and Clearance Side Marker Light with the Reflector. Now, this red square light can be used as a clearance or a side marker light, and also the red lens used on this as reflectorized, meaning that our separate reflector is not needed for DOT compliance. The measurements on this light, just to give you an idea of the length, two and three quarter inches long, the width two and one eighth inches wide, and the depth of it is only one inch deep. Now, this light does feature replaceable screw down lens and an easy to replace incandescent bulb. If you notice in the back, it has a single lead wire for power, and it grounds through the mounting stud.

Now, I do wanna hook this up to some 12-volt power, just to show you how bright the light is. So we're gonna go ahead and take our power wire, and we'll go ahead and hook that up to the single wire lead. And as we mentioned, we're gonna ground it through the stud back here. So with it all hooked up, we'll go ahead and turn our power on, and you'll be able to see the light come on. And then I'm gonna go ahead and turn off the overhead light, and you can see the incandescent bulb lit up, shows you how bright the light is.

Go ahead and turn back on our overhead lights. Go ahead and turn off our power. Now, there's a molded plastic housing and a nice durable lens, which provides all-weather protection against corrosion. Now, on the manufacturer's cross reference, this slide will work as an exact replacement for the Uni Bond, part number MR2020R, the Wesbar, part number 3103, and the Peterson, part number 114R. But that should do it for the review on this Optronics Red Square Trailer and Clearance Side Marker Light with the Reflector.

.

Customer Satisfaction Score:

Ratings & Reviews

4.9

4120 reviews
5 Stars
(3689)
4 Stars
(333)
3 Stars
(53)
2 Stars
(17)
1 Star
(28)
Review sort icon
2-3/4" L x 2-1/8" W x 1" D; Reflectorized lens; corrosion resistant; replaceable lens and bulb; mount on stud; 1-wire; 1-bulb incandescent

by:

These lights are nice for the money , They fit my trailer perfectly. And I received them in very good time , Packaging was very good also.



by:

The purchase was what I expected, it was well packed and delivered very quickly. I would order from etrailer.com again.



by:

Great product description, quick delivery, installed shortly after delivered. Large select of products and will use again on my next project. Thxs



by:

Wide selection of products, fast shipping and helpful videos



by:

excellent fit, good quality, good price, fast shipping



by:

Exactly what I needed, and will need again, and again.....for my boat trailer (which apparently has a "hit me" sign on it)



by:

perfect replacement for oem lights on trailer at a much better price



by:

Factory replacement on my Kauffman open trailer. Easy install and work as expected.



by:

Everything arrived promptly just as I had been informed and in great condition. Have had great experience with etrailer oN multiple occasions and will continue to look to you for your exceptional customer support in the future. Thanks agaiN for your help!



by:

Quick shipping and the lights look great. Haven't installed yet.

Thanks for your help.



by:

Very happy with the trailer light bought from eTrailer, fast shipment and great product!



by:

The marker lights were exactly what I was looking for. The shipping was prompt and everything arrived in excellent condition.



by:

Very happy with the tail light covers I received. They were the right fit and arrived quickly. Would buy again from etrailer anytime.



by:

The Product was as Advertised. It was just what I needed for my Flatbed Trailer.
The service on this order was GREAT. Thank You!
Great Follow-up and informative.



by:

Easy ordering! Fast shipping! Product as described! Would definitely buy from etrailer again!



by:

I got the exact replacement lights I needed for my trailer. Arrived on time. Good customer service!



by:

Great store to deal with. My order was shipped immediately and lots of Email sent from order to shipping information. Order was shipped the same day it was received. I will be back to order my new tires and wheels at some point this year.



by:

The only lights that will fit on our trailer. Glad you have them in stock!

Bruce profile picture

Bruce

11/11/2023

Working great - just have a problem with people crushing them when they load the trailer with their big tractor tires



by:

Product was exactly as described and replaced broken one perfectly. Item was shipped and received in very good time.I would recommend this company (E-trailer ) for any of your trailer lights you may be looking to buy!Thank you for a great product and great service! Thank You



by:

I just bought the light for the lense. It replaced the broken one on my trailer perfectly. I searched all over and couldn't find just a lense.



by:

Exactly as displayed. Neatly packaged. Price is lower than stores yet better quality. Delivered earlier than expected. I Used 6 (3 on each side) to make brake and tail lights for my trailer. Our forklift drivers kept breaking the bulky, hanging from the side of trailer, regular taillights purchased at retailers which used to cause so many problems. This practically eliminated the problem. Lights cant get caught where they are at and are almost flush to the trailer.



by:

Great lights at a great price. Actually I should have ordered the amber lights for the front corner of my trailer instead. However, I went ahead an ordered the whole trailer light kit anyway and use these red lights for the middle of the trailer since it's a long trailer. The lights themselves are well constructed and water tight. They are very visible at night and even have a built in reflector. Mounting was easy with one bolt to attach to the trailer so it makes it easy to replace if needed. As always, very satisfied with etrailer since I have been doing business with them for many years and always get high quality parts at a competitive price. I will share my photo when all my lights are installed.



by:

Clearance lights look and work great they added the extra touch I wanted for my trailer

To L. profile picture

To L.

8/25/2018

Lights still working great



by:

Seems to be a nice unit. Shipping was slower than expected with no tracking info available. May have been a USPS issue as far as time in as much package stamped "damaged when received".

Jay S. profile picture

Jay S.

2/20/2015

Well actually I sold the trailer that I originally bought them for. But I had ordered extra and they will fit new trailer just fine. A very nice product for the price.



by:

The red ones are really hard to find..... very reasonably priced, super fast shipping. Website easy to use/simple to order. Excellent customer service. EVERY product I have ordered from these people has 110% quality and exactly as described ant see the red ones on the back in the picture,sorry.


25
25

See what our Experts say about this Optronics Trailer Lights

  • Are Red & Amber Square Trailer Clearance and Side Marker Light Submersible
    Hello Michael, The Square Trailer Clearance and Side Marker Light with Reflex Reflector - Amber # MC37AB and Red # MC36RB are only available in non-submersible versions. There isn't a light with the exact same 2-3/4" L x 2-1/8" W dimensions that is submersible but we do have options that are submersible like the 2-1/2" x 1-3/16" Thinline LED Clearance and Side Marker Light - Amber # AL91AB and Red # AL91RB.
    view full answer...
  • One Wire Clearance and Side Marker Light Options to Replace Lights on Horton Hauler Trailer
    We have quite a few different options for trailer clearance lights with one wire and that will ground through the mounting hardware. These lights come in various sizes and shapes. The best replacement for your trailer will depend on the size light you are wanting to replace. For a small LED clearance light that is a stud-mount, you can use the Optronics Sealed Mini Rectangular LED Stud Mount Trailer Clearance Light. For an amber light you will want # MCL95AB and for a red light # MCL95RB....
    view full answer...
  • Dimensions of Optronics Replacement Side Marker Lens A36RB
    I pulled one of the # A36RB lenses from the warehouse and it measures 2-13/16 inches wide by 2-1/16 inches long. The mounting holes are 2-3/8 inches apart. This lens fits the Optronics side marker light # MC36RB which measures 2-3/4 inches long by 2-1/8 inches wide by 1 inch deep. I am including a picture that shows the dimensions.
    view full answer...
    Image 1 for
  • Where is the Location of the Part Number on a Trailer Light
    Most, but not all, trailer lights should have the number printed on the back of the light base. I have attached a photo of the Trailer Tail Light # STL8RB that you referenced where you can see the part number highlighted. In the case of a light like the part # MC36RB not having a part number on the back you can take some measurements and send in a picture and we can typically let you know if we have a replacement or not.
    view full answer...
    Image 1 for
  • What is Gauge of Wire Used for Side Marker Light with Reflector # MC36RB
    The gauge of wire that the Square Trailer Clearance, Side Marker Light with Reflector # MC36RB uses is 18 gauge. To be safe you may go ahead and use a heavier gauge wire.
    view full answer...

Do you have a question about this Trailer Light?


Info for this part was:

Employee Patrick B
Video Edited:
Patrick B
Employee Jeff D
Installed by:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Brian T
Updated by:
Brian T
Employee Noah M
Updated by:
Noah M

At etrailer we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.