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Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb - Red

Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb - Red

Item # MC42RB
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4-1/16" L x 2-1/8" W x 1-1/8" D; Corrosion resistant; replaceable lens and bulbs; surface mount on 3" centers; 1-wire; 2-bulb incandescent Lowest Prices for the best trailer lights from Optronics. Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb - Red part number MC42RB can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (214)
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Optronics Trailer Lights - MC42RB

  • Clearance Lights
  • Rectangle
  • Incandescent Light
  • Red
  • 4L x 2W Inch
  • Surface Mount
  • Rear Clearance
  • Side Marker
  • Non-Submersible Lights
  • Optronics

4-1/16" L x 2-1/8" W x 1-1/8" D; Corrosion resistant; replaceable lens and bulbs; surface mount on 3" centers; 1-wire; 2-bulb incandescent

Double-Bullseye Trailer Clearance and Side Marker Light, Two-Bulb - Red

This double bullseye light can be used as a clearance or marker light. The dual-bulb, red light measures 4-1/16" long x 2-1/8" wide x 1-1/8" deep. The molded plastic housing and durable lens provide all-weather protection against. corrosion. The two-bulb design greatly increases the light output. The light features a replaceable, snap-on lens on a black plastic base and easy-to-replace bulbs. The light mounts on standard 3" centers. The light contains a single lead wire for power and is grounded through the mounting hardware.

  • Red light functions as clearance, side marker light
  • Weather and corrosion resistant
  • Dual bulbs increase light output
  • Single-wire design grounds through mounting hardware
  • Surface mounts on 3" centers
  • Dimensions: 4-1/16" L x 2-1/8" W x 1-1/8" D
  • Replaceable lens and bulb

Manufacturer Cross Reference
Light will work as an exact replacement for:
Uni Bond # ML2040R
Wesbar # 3441/3445
Truck Lite # 26302R
Grote # 46792
Peterson # 138R

Manufacturer Specifications

Dual bulb, bullseye marker or clearance light with black base. Two-bulb design optimizes light output. Features snap-on, replaceable lens and easy to change replaceable bulbs. All-weather, molded plastic housing and durable lens protect against corrosion. Mounts on industry standard 3" centers. Grounds through mounting hardware.

dimensions of light

MC42RB Red Double Bullseye Marker, Clearance Light by Optronics, Inc.

Alternate part number: MC-42RB

California residents: click here

Video of Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb - Red

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

Video Transcript for Optronics Trailer Lights - Clearance Lights - MC42RB Review

Today we are going to show you Optronics Double Bulls Eye Trailer Clearance and Side Marker Light, part number MC42RB. Inside the light are two light bulbs for increased light output. It's a single wire design meaning we'll have a single power wire lead, and the light will ground electrically through the hardware used to mount it on the trailer. Both the bulbs and the lens are user replaceable. It's designed to surface mount on your trailer using the mounting holes that are three inches on center.

Next we are going to hook the light up to a power supply so you can see what it looks like when lit up. We'll connect our ground to the mounting hardware, and our power to the wire. Next we'll turn off the overhead lights so you can see what it looks like in the dark. And that's it for Optronics Double Bulls Eye Trailer Clearance and Side Marker Light, part number MC42RB.

Customer Reviews

Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb - Red - MC42RB

Average Customer Rating:  4.8 out of 5 stars   (214 Customer Reviews)

4-1/16" L x 2-1/8" W x 1-1/8" D; Corrosion resistant; replaceable lens and bulbs; surface mount on 3" centers; 1-wire; 2-bulb incandescent


Product was exactly as described.


Trailer Clearance Lights #MC42RB, easily installed, nice lights. There could be a little more space (maybe 1/8" in depth) on the backside so the wire could be positioned through an existing hole in the trailer and the light assy would sit completely flat against the trailer. Seems to be good value for the money and they are cheap.

They are still working great after a year. Good value.
Wayne B - 03/13/2018


I would recommend anyone to purchase from the product I received was as expected and what I needed. Price's are good the service is really good hard to find a business that cares what you get and ready to help if you need it. Also their videos are very informative if your not sure what your doing they do a very good job walking you through it. I will definitely use them again in the future.

Thank you for the concern, Everything I purchased from you are working as they should. VERY HAPPY with all.
Dennis W - 06/17/2016


Excellent quality lights!


I want to keep the original look of my Airstream and the Double Bullseye lights are a perfect very cost effective replacement They add a nice new fresh look and keep the vintage appeal. I replaced all the yellow and red lights for a fresh look.


I was fixing up a vintage Shasta trailer that needed new lights and your products were just what I needed. Thank you very much for the great service.


Thanks again etrailer for a job well done. great clearance lights, fast delivery.
Third time ordering from etrailer and my experience as been perfect every time.


Nothing but RAVE reviews for Parts were exactly as ordered, great price, fit perfectly. Couldn't be more elated with the fast service too!


Great replacement light. These light are very similar to what was on the vehicle. The vehicle is a restored " Mobile Man Cave" / race support vehicle (1979 E-350 box van). I also needed a little assistance from Customer support and Cathy was very helpful. Fantastic experience all the way around. Thanks.


I used the lights on my old cub cadet tractor. Perfect replacement.

Still working fine - thanks
tony c - 11/03/2017


Replaced 40 year old clearance lights with this item. Working great after one year. Very well pleased.


my order was delivered on a timely manner and was in good condition. It Was what I ordered.I am Very happy With etrailer and Will order more items when necessary. Thanks


Very happy with all products


Lights were exactly what I was looking for... Fast delivery, good price, worth the money spent...Great quality lights..(trailer lights)


A very nice look light.You cant go wrong with 2 light.With the money I saved ,I will pop in some LED lights


These were just what I was looking for. No more trying to find the bulb for the others that these replace. Installation was very easy. Just cut and splice.


Factory replacement.for 2002 trailer .very brite
Speedy delivery at great price .


OK for the price I guess.
But, boy they
are very cheaply made compared to the 12 year old Peterson lights 138R lights that I had removed.
If it wasn't for the shipping costs, I would have returned them.


I am very happy to have bough the marker lights, I'm ordering more to replace old ones on my Ford F-550


Exactly as described, fast shipping, excellent service once again!


Exactly what I was looking for. Direct bolt-on for a fair price extremely fast shipping what else could you ask for?


These lights last longer than your trailer will.




Great quality, Great service
Curt L


Ordered for the second time, because I didn't order enough the first time. Replacing marker lights on RV. Easy to work with, look better than current lights and are brighter. Very Pleased.

Show More Reviews

Ask the Experts about this Optronics Trailer Lights

  • Which Optronic Replacement Marker Lights will fit in the Optronics Chrome Trailer Light Bracket
    Double Bull's-eye LED Trailer Clearance and Side Marker Light # MCL45AB and # MCL45RB will fit with Chrome Trailer Light Bracket # BK42CB. These two lights will be a little tighter fit. Double Bull's-eye Trailer Clearance, Side Marker Light # MC42RB and # MC42AB will also work with # BK42CB. I have linked a video for you as well.
    view full answer...
  • Recommended Interior Lights for Utility Van
    I do have a solution for you for interior lights for your utility van but the Optronics # MC42RB Double Bullseye Trailer Clearance Light does not have a clear lens available. What I do suggest is their Rectangular Porch and Utility Light with Switch # RVPL3C or the version without the switch, part # RVPL1C. Both offer a surface-mount housing like the MC42RB. If you prefer high-efficiency LED lights for reduced power consumption and heat then you might consider the Optronics Opti-Brite...
    view full answer...
  • Troubleshooting Trailer Lighting Where Only One Running Light Works
    Since all of your trailer lights operate properly with the exception of one of the running lights, this tells us that the vehicle wiring harness is probably working properly. I would first carefully check the bad light's ground and power wires to ensure that both are secured. If the light uses a separate ground wire, usually a white wire like on # MCL36AB, that ground wire needs to be affixed to the trailer frame, to a clean rust-free bare metal surface. If the light is the type that uses...
    view full answer...

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