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Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb - Amber
(142 reviews)
Price: $5.00
In Stock
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Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb - Amber
Part Number: MC42AB
In Stock
$5.00
Retail:$10.13
You Save: 51%
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- All Info
- Reviews (142)
- Q & A (0)
- Photos
Optronics Trailer Lights - MC42AB
Highlights
- Brighter Amber Output: Dual-bulb design greatly boosts light visibility for clearance and marking.
- Easy One-Wire Hookup: Grounds through the mounting hardware for a quick, clean install.
- Compact Fit: Measures 4-1/16" Lx2-1/8" Wx1-1/8" D to fit standard 3" mounting centers.
- Long-Term Use: Replaceable snap-on lens and bulbs make maintenance simple and affordable.
- Built to Last: Molded plastic housing and durable lens resist corrosion and weather.
- Efficient Power Draw: Each bulb uses .4 amps ( .8 amps total ) to minimize strain on your wiring.
Features to know about
Brighter Coverage When You Need It: Dual-Bulb Amber Output
When visibility matters, the dual-bulb setup on this Double Bullseye light makes a real difference. The two incandescent bulbs work together to increase total light output, giving you better coverage for clearance and side marking. Each bulb draws just 0.4 amps, so the total draw is only 0.8 amps while still putting out a strong amber signal that stands out in low-light conditions.
Built to Handle the Elements: Corrosion-Resistant Housing
Road spray and moisture are no match for its molded plastic housing and durable lens. The all-weather construction resists corrosion and protects the internal components from grime and wear. That means you get steady performance in rain or shine without worrying about rust or shorted connections.
Quick Fixes Made Simple: Replaceable Lens and Bulbs
No need to toss the whole light when a bulb burns out. The snap-on lens removes easily, giving you direct access to the replaceable bulbs. With standard parts like the 194 bulb, it’s simple to keep this light working like new without special tools or rewiring.
Clean and Simple Install: One-Wire Ground Through Mounting Hardware
Wiring doesn’t get easier than this. The single lead wire handles power, and the ground runs straight through the mounting hardware—no separate ground wire needed. The surface mount design lines up with standard 3" centers, making it a quick, direct fit on most setups.
Compact Size That Fits Right In: 4-1/16" x 2-1/8" x 1-1/8"
At just over four inches long and barely more than an inch thick, this rectangular light tucks into tight spots without sticking out awkwardly. It gives you a clean look that matches common mount patterns while keeping your trailer visible and compliant.
Specs
Electrical
- Amperage draw: 0.4 amps per bulb (0.8 amps total)
- Wiring: Single lead wire for power; grounds through mounting hardware
- Bulb type: Two-bulb incandescent design
- Replaceable bulb: Yes
Mounting
- Mount type: Surface mount
- Mounting centers: 3"
- Ground type: Through mounting hardware
Dimensions
- Length: 4-1/16"
- Width: 2-1/8"
- Depth: 1-1/8"
Construction
- Lens: Snap-on, replaceable
- Housing: Black molded plastic
- Weather resistance: All-weather, corrosion resistant
Function
- Light functions: Clearance light, side marker light
- Lens color: Amber
Manufacturer Cross Reference
- Uni Bond #: ML2040A
- Wesbar #: 3440/3444
- Truck Lite #: 26302Y
- Grote #: 46793
- Peterson #: 138A
MC42AB Amber Double Bullseye Marker, Clearance Light by Optronics, Inc.
Alternate part number: MC-42AB
Customer Satisfaction Score:
98% were satisfied with this product
2% of customers were not satisfied
- Product did not meet expectations
- Alternate product found
Ratings & Reviews
4.8
142 reviews
by:
Brent
02/07/2026
2001
Airstream
Excella Travel Trailer
Great product but really was impressed with the customer service messages and quick shipment/delivery service...thank you!
by:
Wayne B
03/13/2017
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.
by:
Brent
02/19/2026
2001
Airstream
Excella Travel Trailer
No sense in totally converting to LED when these are availble...like the black base
by:
John N
12/19/2016
1996
Chevrolet
C/K Series Pickup
Fast shipping, product was good. Easy mount. I am working on a gooseneck trailer trying to get it wired up. Still a work in progress, but these will help tremendously.
John N.
12/19/2017
The lights are working fine, no problems at all. Very pleased.
by:
Paul
10/23/2025
Easy to install! Really like the double lights
by:
jim h
05/07/2013
Wanted to add a few lights and fix broken fender lights on my trailer. you had a great product with a great price with fast shipping couldn't be happier. Just orderd brakes from you and I wiil do buisness again with you.
Very satisfied customer, thanks,
Jim
Very satisfied customer, thanks,
Jim
by:
Harry
05/23/2015
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.
by:
Rick C
07/30/2014
As advertised and fast shipping. Thanks
Rick C.
7/30/2015
Great products at good prices.
by:
Gary
11/10/2018
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.
by:
Clem P.
02/23/2017
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.
Third time ordering from etrailer and my experience as been perfect every time.
by:
Bill H
07/06/2015
1979
Ford
E-350
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.
by:
Chuck S.
10/08/2016
Nothing but RAVE reviews for eTrailer.com Parts were exactly as ordered, great price, fit perfectly. Couldn't be more elated with the fast service too!
by:
JC
05/02/2015
Other companies would benefit to follow etrailer's practices of complete services to its customers. From pricing to installation...they seem to have it all. I've ordered several times and never have been disappointed.
by:
Tom R.
05/14/2017
Replaced 40 year old clearance lights with this item. Working great after one year. Very well pleased.
by:
John
05/21/2019
Good high visibility side marker lights at a great price.
by:
Vaguy
06/18/2020
I used these as they are a perfect replacement for 70s airstreams and they worked great- i assume they are still working great but a little bit ago i sold the trailer.
by:
Chad B
12/05/2014
A very nice look light.You cant go wrong with 2 light.With the money I saved ,I will pop in some LED lights
by:
G Brown
03/31/2020
Easy ordering, fast shipping, prefect fit.
by:
Josh
01/07/2019
Lights were exactly what I was looking for... Fast delivery, good price, worth the money spent...Great quality lights..(trailer lights)
by:
Edgar
05/05/2016
2000
Dodge
Dakota
Great product. Easy to install and the cover doesnt crack with the sun ray .
by:
Rob P.
09/06/2016
Excellent product and fast shipping will use again!!!
by:
John
12/22/2019
Fast service. Just the perfect replacement light for my trailer.
by:
Alvin
05/23/2015
2009
Ford
F-150
These were just what I was looking for, no more driving all over to find the right bulb for the others that thes replaced. Installation was easy. Just cut and splice
by:
David
10/18/2018
good products & fast service I'll always check your site first when I need something.
by:
Fred
04/24/2018
2006
Ford
Van
Fast shipping nice lights.
25
142
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Show More Reviews
See what our Experts say about this Optronics Trailer Lights
- What Red Incandescent Side Clearance Light do You Have to Match My TMC 2294?Hello C.J., Looks like you already ordered the matching one! The Peterson Double Bullseye Clearance and Side Marker Trailer Light - 2 Bulbs - Red Lens # 425800 will be the best match if you have a white housing. If your housing is black, you will want the Double Bullseye Trailer Clearance and Side Marker Light - Two Bulb - Red # MC42RB. So what happened to the missing one? Or is that a mystery in itself?
view full answer... - Replacement Light For A Reflect-O-Lite 300 Trailer Side Marker LightThe Replacement Amber Lens for MC42AB Trailer Lights A42AB is designed for the Double Bullseye Trailer Clearance, Side Marker Light, Two-Bulb # MC42AB, and will not work for your Reflect-O-Lite 300, however I have another solution. Reflect-O-Lite has been discontinued for a while now, so there are not replacement parts available, unfortunately. Instead, I recommend replacing the entire light with the Trailer Clearance or Side Marker Light w/ Reflex Reflector # MC32AB, with the butt connectors...
view full answer... - One Wire Clearance and Side Marker Light Options to Replace Lights on Horton Hauler TrailerWe 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... - Amperage Draw of the Double Bullseye Trailer Clearance, Side Marker Light # MC42ABThe bulb that is in the Double Bullseye Trailer Clearance, Side Marker Light # MC42AB draws .4 amps. Since this light has two bulbs it would draw a total of .8 amps. I also attached a review video for this light for you to check out as well.
view full answer... - How to Make Marker/Clearance Light Function like Turn SignalWe offer the Optronics # MC42AB, which looks like it's an equivalent to the Do Ray AS 105A lamp you mentioned. The lamp is a single function lamp, it could only be used as a marker/clearance light or a turn signal, but not both. If you wanted to use the lamp as a turn signal, you'd need to use a vehicle to vehicle converter like part # 118158. I'll link you to a diagram that shows how to wire the marker lights and the converter so the lamps would operate as turn signals.
view full answer...
- Replacement Bulb Recommendation for a Double Bullseye Trailer Clearance Light MC45ABThe correct replacement bulb for the # MC45AB light will be the 194 bulb part # A194B.
view full answer... - Are Bulbs Included with the Double Bullseye Trailer Clearance, Side Marker LightThe 2 bulbs are included with the Double Bullseye Trailer Clearance, Side Marker Light # MC42AB so you don't have to worry about grabbing some of those to use this light. Attached is an installation video that you can check out.
view full answer... - Can Motorcycle Taillight Wiring Be Combined so that Trailer Taillight Could be UsedI've done a similar conversion on my streetbike. Since motorcycles have the stop and turn signals on different circuits you need a converter to allow you to get them combined onto the same circuit. For that you'd need the part # RM-732. You'd wire you current taillight wiring to the input side of this and then on the output side you'd have the circuits combined like you are needing.
view full answer... - Which Optronic Replacement Marker Lights will fit in the Optronics Chrome Trailer Light BracketDouble 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... - Is There an Amber, Double Bulb, Trailer Clearance Light with a White Back Instead of a Black BackWe do have a light very similar to the Optronics Double Bullseye Trailer light # MC42AB that you referenced that has a white background. The Peterson Amber Rectangular Two Bulb Trailer Clearance Light part # 425600. This light does have the white background mounting surface that you had requested. This light has very similar dimensions, mounting style, and bulb configuration as the product that you had referenced. I have included a link to the product page for your reference.
view full answer... - Double Bullseye Trailer Clearance Marker Light # MC42AB on Travel Trailer w/ Lighting Ground WireSince the Double Bullseye Trailer Clearance Side Marker Light, # MC42AB, grounds through the lighting hardware to the trailer frame, the ground wire from the previous light on your 1985 Funtime Travel Trailer is not needed. This wire could be secured to the back of the lights or just tucked away up under the trailer.
view full answer... - Availability of Optronics Double Bullseye Clearance Light with Black BaseThe Double Bullseye Optronics clearance lights like the # MCL45AB have 8 diodes not 10. For a black base you'd want # MC42AB.
view full answer... - Amperage Draw of the Double Bullseye Trailer Clearance, Side Marker Light # MC42AB Actually I checked with Optronics and they list that the Double Bullseye Trailer Clearance, Side Marker Light # MC42AB that you referenced only draws .4 amps. So for a total of these you would only be drawing 3.2 amps.
view full answer...
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Wayne B.
3/13/2018
Still working great after a year, good value.