Optronics LED Trailer Utility Light - Submersible - 10 Diodes - Oval - Clear Lens

Optronics LED Trailer Utility Light - Submersible - 10 Diodes - Oval - Clear Lens

Item # BUL78C3MB

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Optronics LED Trailer Utility Light - Submersible - 10 Diodes - Oval - Clear Lens White BUL78C3MB
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  • Utility Lights
  • Oval
  • LED Light
  • White
  • Surface Mount
  • 7-1/2L x 3W Inch
  • Optronics
7-9/16" x 3-5/16" Oval. Waterproof LED utility light provides bright light to illuminate an area. Durable polycarbonate housing and lens. Surface mount with built-in flange - no panel cutout required. Accepts industry standard 3-prong plug. Lowest Prices for the best trailer lights from Optronics. Optronics LED Trailer Utility Light - Submersible - 10 Diodes - Oval - Clear Lens part number BUL78C3MB can be ordered online at etrailer.com or call 800-298-8924 for expert service.

  • All Info
  • Reviews (19)
  • Q & A (11)
  • Videos (1)
  • Photos
  • Why etrailer?

Optronics Trailer Lights - BUL78C3MB

7-9/16" x 3-5/16" Oval. Waterproof LED utility light provides bright light to illuminate an area. Durable polycarbonate housing and lens. Surface mount with built-in flange - no panel cutout required. Accepts industry standard 3-prong plug.


  • LED utility light provides bright light to illuminate an exterior or interior area
    • Not certified for backup light function
  • Sonically sealed, waterproof housing and lens unit is submersible
  • 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
  • Durable polycarbonate housing and lens
  • Clear lens over white LEDs
  • Compatible with 12V DC systems
  • Surface mount with built-in flange - no cutout required
    • Adhesive back allows for easy application
  • Accepts industry standard 2-prong or 3-prong plug


  • Dimensions: 7-9/16" Long x 3-5/16" wide x 3/4" deep
  • Light output:
    • Effective lumen output: 490 lumens
    • Raw lumen output: 700 lumens
  • Diodes: 10
  • Power draw at 12.8V: 0.054 amps
  • Lifetimew warranty on LEDs

Manufacturer Cross Reference

  • This light functions as an exact replacement for:
    • Wesbar EZ

Optronics BUL78 Series LED Utility Light Dimensions

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.

Raw Lumens vs. Effective Lumens

Lumens are used to measure the amount of usable light that is put out by a light source. Raw lumens represent the number of lumens that the manufacturer claims the LEDs are capable of producing. It does not include the light's drive method or the amount of light lost from the lens or reflector. Effective lumens take these factors into account and represent the number of lumens that are actually produced by the complete light assembly, not just the amount of light that the diodes are capable of producing. This light has a 700 raw lumen capacity and produces 490 effective lumens.

BUL78C3MB Optronics LED Trailer Utility Light - Submersible - 10 Diodes - 490 Lumens - Oval - Clear Lens - PL3 Plug

Alternate part number: BUL-78C3MB

California residents: click here

Video of Optronics LED Trailer Utility Light - Submersible - 10 Diodes - Oval - Clear Lens

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

Video Transcript for Optronics Trailer Lights - Utility Lights - BUL78C3MB Review

Today we are going to look at Optronics Sealed 6 Oval LED Trailer Utility Light, part number BUL78C3MB. The light is sealed and water proofed, and its designed to be a surface mount light. There are 10 clear super LEDs inside that draw a total of .080 amps at 12.8 volts. Its a 2 wire plug in design that has a quick connector and features 2 wires, one for ground and one for power. On the back you will also find adhesive that you can use to attach the light if screws aren't needed. Next we'll hook up the light to a power supply so you can see what it looks like lit up.

Connect our ground to the ground wire contact, and our power to the other. Next we'll turn off the overhead lights so you can see what it looks like at dark. And that does it for the Optronics Sealed 6' Oval LED Trailer Utility Light, part number BUL78C3MB. .

Customer Reviews

Optronics LED Trailer Utility Light - Submersible - 10 Diodes - Oval - Clear Lens - BUL78C3MB

Average Customer Rating:  4.9 out of 5 stars   (19 Customer Reviews)

7-9/16" x 3-5/16" Oval. Waterproof LED utility light provides bright light to illuminate an area. Durable polycarbonate housing and lens. Surface mount with built-in flange - no panel cutout required. Accepts industry standard 3-prong plug.


Great quality, and very bright. I used two of these to replace the single incandescent light in my enclosed 6'x10' cargo trailer. Less batter drain and better lighting than before. Very pleased. 41911




Easy to install. I used them as switched utility lights for backing the trailer into a driveway, not as backup lights. Flush mount is perfect for not drilling hole in the trailer frame. Enough light for what I needed. The waterproofing will be tested every time I launch. 258730


these lights are great for boat trailer on backing up,plus lets others no also. 583774


Great brightness 372490


Installed on 92 boat trailer. Best money ever spent. Backing down ramps in dark, lights it up great. Best value and price I found. Should have done it years ago. 327212


Exactly what I needed. Will buy for other trailers.

Ellis - 12/22/2017



Perfect as always! 295487


I use them as backup lights on my truck. They are very bright at night, and light up a lot of area. Works great with my backup camera. And they are very easy to install. 275019


Great, very satisfied.

Mark A - 07/22/2017



great product and easy online ordering. 225384


Exactly as described on the website. Easy to install and bright! 210139


Great lights!! Works like the day they were installed.

Jeff W - 07/07/2016



Great product. Great service. Received the lights in 4 days standard shipping. I mounted them on my boat trailer as back up lights and not only do they work great but also look good on the trailer. The only difficulties was running an extra wire. I attached the power wire to my surge brake override solenoid. My trailer is a tube steel trailer but using a fish tape done the job. The total job took about 1 hr. 179137


Got some water in them but they are still working .

Andy R - 03/17/2016



Was just what I was looking for. I have not installed yet will be doing it this weekend. I have hook up light to a power source and its pretty darn bright. 168116


the lights arrived as ordered--timely and intact. havn't used them yet 122257


Great product. Just installed tonight on my 2011 Nitro Z-7 Trailer. Looks great and very bright. Thanks for a great product and delivery. 94065


No issues whats so ever. Great product.

Billy T - 08/08/2014



Great product! Lightweight, bright and easy to install. Bill 71919


Bright as head lights! 66702


Nice and bright work good 58639


Easy to work with, like the fact that they look nice and don't need a large hole to be mounted. The lights were mounted on the back of a trailer to be use ad back up light and work very well at illuminating the dark. 13387


great light 7137


Ask the Experts about this Optronics Trailer Lights

Do you have a question about this Trailer Light?

  • LED Reverse Light for Trailer with Limited Space
  • One option for a DOT approved LED reverse light is Sealed, 6" Oval, LED Trailer Utility Light, Adhesive Mount, 10 Super Diode - Clear Item # BUL78C3MB. It is 7-9/16" x 3-5/16" x 3/4". You mentioned there isn't a lot of space available. How much space do you have? There are not a lot of DOT approved reverse lights available so another option is to use light # BUL10CB with grommet # A70GB and bracket # BK70BB and pigtail # A49PB. Then you can mount the light in the bracket off of the frame.
    view full answer...

  • Recommended 6 Inch Oval LED Backup Light For Brightness
  • We have 6-1/2 inch oval LED lights that are very bright, that are typically referred to as 6 inch lights in the trailer industry. I recommend the Optronics GloLight LED Backup Light for Truck or Trailer - Submersible - 22 Diodes, # BUL111CB, because it is a very bright replacement light that that meets the DOT compliant standards. They have a very clean look and are sonically sealed so they can handle all the weather thrown at them. They require a recessed mount # a70gb, and a 2-prong...
    view full answer...

  • Very Bright Reverse Light Recommendation for Boat Trailer
  • Best option is the Optronics LED Trailer Utility Light # BUL78C3MB that you mentioned. This is a submersible LED backup light that can put out 490 Lumens so it's your best all around option. We've had other customers with boat trailer come back and say this puts out quite a bit of light and worked great for them!
    view full answer...

  • Backup Light Recommendations for a Enclosed Utility Trailer
  • I spoke with my contact at Optronics and he informed me that this Optronics Trailer Light, part # BUL78C3MB, is certified to be used as a utility light for a trailer but not as a reverse light. He said that if you were to use this as a reverse light he would recommend that you contact your state and local laws to determine if that would be an issue for passing inspections. He also said that these lights will not be as bright as most reverse lights normally are. If you want a similar...
    view full answer...

  • Is the Oval LED Trailer Utility Light a Flood or Spot Light Style for Interior Trailer Lighting
  • The Oval, LED Trailer Utility Light, item # BUL78C3MB, is designed as an area light, more like a flood than a spot light, and would be a good choice for interior lighting in an enclosed cargo trailer. The Straight 3-Wire Pigtail, item # A45PB, can be used for wiring this light. This LED light could be spliced into the tail light circuit, so the lights can be activated with the vehicle tail lights. A switch inside the trailer would be needed so that the lights are not on when traveling down...
    view full answer...

  • Parts Needed to LED Reverse Lamps to Boat Trailer
  • If you wanted to mount an oval reverse lamp on the outboard sides of the wooden guide-ons shown in the photo, you could easily do so using the following parts: LED Submersible Back-Up Lamp, part # BUL10CB (DOT certified for Back Up Lamp Function) Mounting bracket, part # BK70BB Grommet, part # A70GB Wire pigtail, part # A49PB If you wanted to mount the lamp on the metal upright, that would be possible as well but you'd need to box off the upright somehow to provide a surface that...
    view full answer...

  • Reverse or Utility Lights to See When Backing Up Cargo Trailer
  • If your trailer has a 7-Way connector and the vehicle side has the center pin active when the vehicle is in reverse then you can install backup lights on the trailer and wire them to the center pin. You can use 2 of backup light # BUL12CB 2 of grommet # a70gb 2 of bracket # BK70BB And 2 of pigtail # A49PB If you do not have a 7-Way but just a 4-Way instead you could wire a utility light such as # TLL48FB in with the running light wire on the trailer and have the utility light run...
    view full answer...

  • What does Super LED mean in the Optronics Sealed Super LED Trailer Light # BUL78C3MB
  • I spoke with my contact at Optronics and he said that the Super LEDs in the Optronics Sealed Super LED Trailer Light, part # BUL78C3MB, are brighter than the normal LEDs. He gave me a candela output rating on the Super LEDs as 125 cd. He said the candela is the luminous intensity of the light. For comparison he said the candela output on a 100 watt incandescent light bulb in your home is 100 cd.
    view full answer...

  • 24 Volt White Trailer Light Recommendation
  • For a similar light that can be used on a 24 volt system you would want the part # BUL23C24B, but the # BUL78C3MB that you referenced can only be used on a 12 volt system.
    view full answer...

  • Is Bargman 84 Series Trailer Taillight # 47-84-610 Sold Individually or in Pairs
  • The Bargman LED, Surface Mount, Double Tail Light - 84, 85 Series - Red - Black Base Item # 47-84-610 is sold individually. If you needed a pair of these you'd need to order a quantity of 2.
    view full answer...

  • Can I Use Optronics LED Trailer Utility Light # BUL78C3MB On My Garden Tractor for Illumination
  • The item you selected, Sealed 6 Inch Oval LED Trailer Utility Light, part # BUL78C3MB, draws .080 amps at 12.8 volts. The white wire is the ground wire and the red wire is the power wire. You would attach the white wire to a good ground connection point on the tractor and run the red wire to the battery of the tractor. If you want to be able to turn the light on and off, you can use a simple switch like part # D16740.
    view full answer...

Do you have a question about this Trailer Light?

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Info for this part was:

Expert Research:
Michael L
Expert Research:
Robert G
Expert Research:
Michael H
Expert Research:
Jeff D
Expert Research:
Reno H
Expert Research:
Jameson C
Written by:
Tyler C
Updated by:
Brian T

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