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GloLight Thinline LED Trailer Clearance or Side Marker Light - Submersible - Rectangle - Red Lens
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GloLight Thinline LED Trailer Clearance or Side Marker Light - Submersible - Rectangle - Red Lens

Item # MCL165RB
Our Price: $7.70
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Shipping Weight: 0.08 lbs
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3-7/8" x 1-1/4" x 7/8". Waterproof, LED trailer light serves as a side marker light or a clearance light. GloLight lens creates a solid panel of light. Wiring and bracket (sold separately) for installation. P2 rated. 10 Diodes. Great Prices for the best trailer lights from Optronics. GloLight Thinline LED Trailer Clearance or Side Marker Light - Submersible - Rectangle - Red Lens part number MCL165RB can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (193)
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  • Videos (2)
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Optronics Trailer Lights - MCL165RB

  • Clearance Lights
  • Rectangle
  • LED Light
  • Red
  • 3-7/8L x 1-1/4W Inch
  • Surface Mount
  • Rear Clearance
  • Side Marker
  • Submersible Lights
  • Optronics

3-7/8" x 1-1/4" x 7/8". Waterproof, LED trailer light serves as a side marker light or a clearance light. GloLight lens creates a solid panel of light. Wiring and bracket (sold separately) for installation. P2 rated. 10 Diodes.


  • Rectangular trailer light can function as both a clearance light and a side marker light when properly mounted
  • Thinline Series has a low profile so that light can fit in tight spaces
  • GloLight lens creates a solid light pattern with a smooth appearance
  • Sonically sealed, waterproof housing and lens unit is submersible
  • Durable surface-mount technology (SMT) construction of LED circuit board
    • Better withstands shock and vibration
    • Allows for improved heat distribution
  • LEDs make great replacements for incandescent lights
    • Last 50 times longer
    • More efficient - provide brighter light with less power output
    • No bulbs to replace - no brittle filaments
  • Red lens over white LEDs
  • Durable polycarbonate housing and acrylic lens
  • Mounts on surface of trailer with built-in flange - hardware not included
  • Requires wiring and mounting bracket (A65B - sold separately) for installation
  • P2 rated


  • Quantity: 1 clearance/marker light
  • Diodes: 10
  • Dimensions: 3-7/8" long x 1-1/4" tall x 7/8" deep
  • Power draw at 12.8 volts: 0.09 amps
  • Lifetime warranty on LEDs

MCL165 Series Dimensions

Innovative GloLight Design

This red LED light serves as either a side marker light or a clearance light. The light gives your truck or trailer a distinctive look that's completely street legal. This Optronics GloLight has a unique solid light pattern when lit, so your lights stand out from the rest. Optronics GloLights are a great way to add both style and value to your truck or trailer.

Sonically Sealed, Waterproof Trailer Light

The waterproof construction of this light makes it ideal for use on trailers that may be submerged, like a boat trailer. The housing and lens are sonically sealed together to create a single unit, which means that water will not get into the light and damage the diodes or circuit board.

LEDs vs. Incandescent Lights

The long-lasting, cool-burning LEDs make this light the perfect replacement for incandescent trailer lighting. LED lights are more efficient, use less power, and last much longer than incandescent lights.

P2-Rated Lights

Diagram of light spread for P2 rated light

A P2-rated light produces a 45-degree angle of light to either side of its centerline for a total of 90 degrees of coverage. This beam pattern can be seen straight on, but it cannot be seen clearly from the side. So this type of light can be used as either a side marker light or a clearance light, but it cannot function as both. If you need both functions, then you must install 2 separate lights on your trailer - one as a front or rear clearance light and one as a side marker light.

Surface-Mount Light

Surface mount light

Surface-mount lights install flat against the surface of the trailer, so a hole does not need to be cut into the trailer for the light. This type of light is installed using a flange or bracket that has mounting holes. And mounting hardware is used to secure the light to the trailer.

MCL165RB GloLight Thinline LED Trailer Clearance or Side Marker Light - Submersible - 10 Diodes - Rectangle - Red Lens

California residents: click here

Video of GloLight Thinline LED Trailer Clearance or Side Marker Light - Submersible - Rectangle - Red Lens

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

Video Transcript for Optronics GloLight Thinline LED Clearance Light Review

On this enclosed trailer, we're going to review and install the Glow Light Thin Line Clearance Light. Part number MCL165AB. Now we're working with the amber color today, this is also available in red as part number MCL165RB. This is our light right here. Couple of things dealing with the length, is going to be 3 7/8 inches long. From here to here, 1 1/4 high, and the thickness from here to here is going to be 7/8 of an inch.

Take a look at the backside, two simple poles, one's going to be ground, one's going to be hot. Very simple to install. This part number you get this entire assembly right here. The base such as in this example right here, is sold separately. This is a completely sealed unit, so you can use this .. There's a clearance side application right here, or you can use it in marine trailer applications as well.

Now this is an LED light, and this uses ten diodes. It's a very super bright light. Very easy to install, let's go ahead and do that. Set our new one to the side, and remove our preexisting light. Now there's a catch on each side, and on the inside as well where the contacts are, is a press fit. inaudible 00:01:07 similar to remove and install.

We'll use a flat bit screwdriver to kind of release the edges, and pull out on it. You may have to pry around a little bit on it as well, to get it to come out. A little patience and it pops right out. Maybe a good idea to go and clean this area out first, and then install our new light. It may help to use some kind of tool to probe around in there, and clean out the tabs.

Maybe scratch it up a little bit to. Make sure you have good contact, and get rid of the dirt. We'll take our new light, and put it into place. Line up the contacts, and push it in. That's all it takes. We'll go ahead and apply power to it, and make sure it works. Of course we're in daylight, it's a little bit harder to see, but look closely we got we got one, two, three, four points of light on our clearance light here, compared to a conventional two bulb incandescent setup here. With that, that will finish it for a Glow Light Thin Line Clearance Light from Optronics. Part number MCL165AB.

Customer Satisfaction Score:

Customer Reviews

GloLight Thinline LED Trailer Clearance or Side Marker Light - Submersible - Rectangle - Red Lens - MCL165RB

Average Customer Rating:  4.7 out of 5 stars   (193 Customer Reviews)

3-7/8" x 1-1/4" x 7/8". Waterproof, LED trailer light serves as a side marker light or a clearance light. GloLight lens creates a solid panel of light. Wiring and bracket (sold separately) for installation. P2 rated. 10 Diodes.


These replacement lights were exactly the same as what was originally on my trailer!! Easy to install!! Website was easy to navigate!! Thank you !!


I spent a lot of time on the internet looking for bright LED clearance lights. I happened upon these GloLight marker lights. I was a little hesitant but have been nothing but pleased. The lights seem to be of sufficient build to keep the water out for years to come. Many LED lights put light out in a straight patter I wanted a light that gave general area lighting and this fits the bill. I drive a lot in the pitch black. It is nice to be able to clearly see where my trailer is at at all times. I would definitely purchase these lights again. I purchased the amber as well as red marker lights. I also purchased the tail markers and the effect was dramatic. Way brighter than the old LEDs I had on it.


Did what its supposed to.

should be shown when the lights are purchased, and recommended. Some of us don't realize they are needed when we buy the lights that they are used for.


Trying to swap out my trailer lights to LED, so the draw on the battery is minimal. There are so many variations on the solid color, I had to measure and keep measuring. The solids have 10 Led’s But no such luck is it’s the fender lights that are both amber and red. I guess one company can’t do it all.
It would be great to include the mounting plates, especially at this price. And also to sell multi packs of two or three. I only need two amber and two fender dual color, but need seven red.
Shipping was sort of slow compared to today’s shipping speeds. Back in the day it would have been speedy. Times they are a changing. Packaging was weak. Each light has a plastic bag, but maybe only two were still in the bag. Maybe some sort of sealed plastic bag would have been smart.
I’m guessing these will work fine. I thought we had to be careful of the Positive and Neutral leads for LED lights because we can damage them if they go on backwards. I guess we shall find out.
Thanks etrailer for actually having this product with such extensive documentation and videos. Other websites ain’t got nothin on you.

Etrailer Expert

Rachael H.


We do have several light bracket options linked at the bottom of each product page for each light. There are different configurations, and colors to suite your specific needs. At this time we do not offer these lights in a multi-pack configuration.



same. Lights dont exactly fit old brackets even though the exact same size.


I installed these on a 2004 haulmark 8.5 by 24 enclosed trailer. When the trailer was originally assembled, the light bases were attached to the trailer with a large pan head screw. These screws are very tall and interfere with the base of these led lenses during installation; meaning the lenses will not snap into place by just a fraction of an inch. Grinding a small amount of material off of the pan head screw gave these lenses enough clearance to snap into place. The lenses appeared to be made very well, and I hope they stand up to ultraviolet light. Very pleased.

Kevin H.


After one year, these lights are proving durable. Very pleased.


Easy to install


In general, I am very pleased with the LED marker lights I ordered. One bit of advice, there is a "zero clearance" fit between the light itself and the mounting base. Therefore, the only screw that will work must be a tapered head which sits, fully recessed, within the mounting holes. The lights did not come with any mounting screws, so you must source your own.


Great value, easy to install, rapid delivery and the right product the first time.

Excellent customer service and the product still works beautiful and looks great!

-2005 Featherlight Horse trailer.

Stewart G.


The lights are still bright and clear. I have a few others on that trailer that are fading, Ill use etrailer again for those!


Great lights. Quality. The holes on the base have a protective grease covered with a piece of tape. They click together great and give off an impressive amount of light.

Cody S.


So far they have been great. Way better quality and brightness than you get from other places.


Great light and brighter than the original ones!


Looks clean and simple. Works well and can be easily replaced if something impacts an area of your trailer.

Easy to install, but make sure you use low profile mounting hardware. A nice low profile screw works well, but a cap head screw will create an interference when clipping this light to it’s mount.


Ordered new LED clearance lights, taillights and clear interior lights to replace the non LED versions. They were shipped immediately with a confirmation. They were exactly as illustrated and what we needed for our horse trailer. Also came at a nice price!!
Would recommend shopping on their site


Much brighter than the stock running li ghts.


Ordered new red & yellow led signal markers and a new lid for the trailer. All arrived in 3-4 days and all the old Lights’s swapped out easy. Trailer looks new!


Good for replacement base of initial install of the glo marker lights. Mine have been on for a year - no problems. I also have used the lights with base included.


I like this new style light from Optronics. Can’t wait to see how they look at night. I will say that some don’t seemed to be manufactured to consistent specs, some (very few) are nearly impossible to snap into the brackets with a reasonable amount of force. Others pop in easily, still a good value for the price point.


My new lights and harness were easy to attain understand and install. It came with everything I needed to rewire and install new lights in out and around my entire trailer.


LED replacement part for my pre-existing non-LED part - works just fine.


Thank you to etrailer for your quick shipping and professional follow up with our Volunteer Fire Department's order. We are updating our concession trailer for a fundraiser event in just a few weeks & your quick turnarounds are helping our deadline for repair. We will definitely purchase from your company again.


I have found that the LEDs burn out much quicker than the incandescent bulbs, but because the LEDs burn out one at a time, I get about the same amount of use. The burn out may be because my alternator puts out nearly 15 volts which exceeds the capacity of the LED. I like the LED light because it is much brighter, even with burned out LEDs.


Works great!!


Lights are a great replacement and are an excact fit. Thay are extreamly bright and have same conectors as stock lights.


Perfect snap in replacement for my old bulb lights


Excellent response. Fast delivery. Product reviews are spot on. Quality products. Can't go wrong with e Trailer.


Products were spot on and service was better than I could ask for. Every order I have placed the service has amazing. They really go out of their way to help in any way possible.

Show More Reviews

See what our Experts say about this Optronics Trailer Lights

  • Available Plastic Mounting Brackets for GloLight Thinline Clearance Lights
    The Black Molded ABS Mounting Bracket for Thinline Series Clearance Lights, # A65B, are compatible with the Optronics GloLight Thinline Lenses, # MCL165RB. The mounting brackets will allow you to mount on standard 3 inch centers and the overall dimensions are 4-1/16" L X 1-1/16" W X 5/8" D.
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  • Red Trailer Clearance Light that is Submersible and LED
    We have the part # MCL165RB which is a submersible red LED trailer clearance light like you said you are looking for. For a mounting bracket with wiring we have the part # A65PB as well to go with it. I attached an install video for this light for you to check out as well.
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  • White Trailer Fenders and Lights for a Bay Liner Trailer with 13" Wheels
    I do have an option for you, but we do not have fenders that already have the lights on them. We do have the Fulton Single Axle Trailer Fenders # F008574-2 which are white and work with wheels up to 14", so they will work with your 13" wheels. You can then add a light using the Black Bracket and Single Wire Plug for Thin Line Series Trailer Clearance and Side Marker Lights # A65PB and the GloLight Thinline LED Trailer Clearance or Side Marker Light # MCL165RB for red or the GloLight Thinline...
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  • Lights for a 7 Foot x 10 Foot Cargo Trailer
    It is imperative you check your local laws for lighting requirements in regards to your specific trailer, though I can tell you you no matter what you'll need stop lights, tail lights, turn signals and reflectors. There are other factors, including your trailer's GVWR that you need to take into consideration; I have added a link to a help article on trailer lighting requirements which I highly recommend checking out. That said, a 7' wide x 10' long cargo trailer is almost certain to have...
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  • Watts of Optronics Lights ILL86BCB, STL211XRFHB, & MCL165RB
    Sure thing; the Optronics LED Step Light # ILL86BCB is 2.176 watts, the Fusion LED Trailer Tail Light # STL211XRFHB is 3.84 watts, and the GloLight Thinline LED Light # MCL165RB is 1.152 watts.
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Do you have a question about this Trailer Light?

Info for this part was:

Employee Jameson C
Expert Research:
Jameson C
Employee Kathleen M
Video Edited:
Kathleen M
Employee Cole B
Installed by:
Cole B
Employee Wilson B
Written by:
Wilson B
Employee Brian T
Updated by:
Brian T

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