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Peterson Trailer License Plate Light - Submersible - Incandescent - Gray Housing - Clear Lens
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Peterson

Peterson Trailer License Plate Light - Submersible - Incandescent - Gray Housing - Clear Lens

Part Number: M439K
149 Reviews | 10 Questions
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$9.74
Retail:$21.12
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peterson trailer lights license plate light - submersible incandescent gray housing clear lens
peterson trailer lights license plate submersible light - incandescent gray housing clear lens
peterson trailer lights license plate submersible m439k
peterson trailer lights license plate submersible m439k
peterson trailer lights license plate light - submersible incandescent gray housing clear lens
peterson trailer lights license plate submersible
peterson trailer lights license plate 3-3/8l x 1-3/4w inch m439k
peterson trailer lights license plate 3-3/8l x 1-3/4w inch
peterson trailer lights license plate 3-3/8l x 1-3/4w inch light - submersible incandescent gray housing clear lens
peterson trailer lights license plate
peterson trailer lights submersible 3-3/8l x 1-3/4w inch m439k

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3-3/8" x 1-3/4" Rectangle. Waterproof, incandescent trailer light illuminates your trailer's license plate. Durable polycarbonate housing and lens. Surface mount with mounting ears - hardware not included. Accepts standard 2-wire plug. Great Prices for the best trailer lights from Peterson. Peterson Trailer License Plate Light - Submersible - Incandescent - Gray Housing - Clear Lens part number M439K can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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Peterson Trailer Lights - M439K

Highlights

  • Always Visible Plates: Clear lens and incandescent bulb keep your license plate well lit.
  • Reliable In Any Weather: Sonically sealed, waterproof unit stays dry even when submerged.
  • Tough Enough for Work Trailers: Polycarbonate housing and lens resist impact and moisture.
  • Simple 2-Wire Hookup: Uses an industry-standard 2-prong plug for easy connection.
  • Quick Surface Mount: Mounting ears align with 2-3/4" hole spacing for a secure install.
  • Exact Replacement Fit: Matches Optronics #LP97CB for direct swap with no rewiring.
Made in USA

Features to know about

Reliable Plate Illumination: Compact and Bright Incandescent Light

Keeping your license plate visible at night is simple with this Peterson incandescent light. The clear lens and bright output illuminate the plate evenly for compliance and safety. Sized at 3-3/8" long x 1-1/4" tall x 2-3/8" thick, it’s compact enough to fit cleanly on most trailer setups without taking up extra space. The standard 12V DC system compatibility and incandescent design make it straightforward and dependable.

Worrying About Water Damage: Sonically Sealed and Submersible

If your trailer sees wet roads or the boat ramp, this light is built for it. The housing and lens are sonically sealed together into a single waterproof unit, keeping water out and protecting the bulb and wiring inside. That sealed design means you can submerge the light without worrying about leaks or corrosion, making it ideal for long-term use in harsh or wet environments.

Quick Mounting with Standard Fit: Surface-Mount Design

Installation stays simple thanks to the surface-mount layout with ear-style flanges. The mounting holes are spaced 2-3/4" center-to-center, so positioning it is easy when replacing an older light or adding a new one. It mounts flush to the trailer surface using your own hardware and connects through an industry-standard 2-prong plug (142-49 sold separately), giving you a clean and sturdy finish without extra adapters.

Durable Construction That Lasts: Polycarbonate Housing and Lens

Built for the long haul, both the housing and lens are made from durable polycarbonate material that resists impact and wear. That toughness helps the light hold up through vibration, weather, and repeated use—keeping your setup looking neat and staying functional season after season.

Specs

Dimensions

  • Overall length: 3-3/8"
  • Overall height: 1-1/4"
  • Overall thickness: 2-3/8"
  • Distance between mounting holes (center on center): 2-3/4"

Technical diagram showing the Peterson M439K submersible trailer license plate light with labeled measurements for overall dimensions and 2-3/4-inch mounting hole spacing.

  • Distance between mounting holes (center on center): 2-3/4"
  • Dimensions: 3-3/8" long x 1-1/4" tall x 2-3/8" thick

Warranty

  • Warranty: 1-Year limited warranty

M439 Peterson License Plate Trailer Light - Submersible - Incandescent - Gray Housing - Surface Mount - Clear Lens







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Customer Satisfaction Score:

Ratings & Reviews

4.8

149 reviews
5 Stars
(131)
4 Stars
(12)
3 Stars
(3)
2 Stars
(2)
1 Star
(1)
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by:
My plug fit, but needed some convincing...just widened the receptor and bingo, it plugged in. My trailer is a 2004, Featherlite.
Happy with product, ordering was easy, fast delivery, good price.
by:
The exact same replacement
by:
Nice product. Excellent service
by:
First time working with etrailer.com and must say that web site made my purchase an easy one. Would not hesitate with future purchases.

The license plate light was for an enclosed snowmobile trailer and I was in need of a replacement that was a simple R&R. The unit was a perfect match along with the hole pattern for mounting. I also had some self taping stainless steel screws that I used to mount the unit due to chemicals used on the road (during winter months) cause corrosion in the NE and wrecks havoc where there is an exposure.
by:
This product is rather simple, but it is exactly what I needed. The factory light that was on my trailer was small, and burnt out. I simply drilled out the old light mounting, removed it, and drilled one new mounting hole for the new light(using one of the old holes). Light works great and the license plate if very visible at night. Quick delivery from eTrailer was very appreciate!
by:
Good quality product. Exactly as described. The only complaint that I have is that there are zero instructions. What instructions would one need for a light? Which wire is used for ground, black or white? This may not be important for an incandescent bulb but reverse voltage will typically blow an LED. If you do house wiring, you expect the white wire to be ground. If your background, like mine, is radio and DC circuits then the DC ground wire is typically black or green. On these lights, the ground is white.
by:
HAVE A NEW TRAILER AND WAS NOT LOOKING TO START ALTERING WIRING. TRIED SEVERAL OF THE LOCAL PARTS HOUSES , BUT COULD NOT FIND MATCH. GOGGLED PART NUMBER AND FOUND EXACT PART, WHICH ARRIVED WITHIN WEEK. NO DRILLING OR SPLICING!

HAPPY THAT ORDER QUANTITY HAD NO MINIMUM, DID NOT NEED A BOX OF FIFTY LIGHTS LAYING AROUND GARAGE, BUT WANTED AT LEAST ONE EXTRA PRICE WAS GOOD THANKS
by:
This company is on of the best places to order your parts from. This is the second time I was able to place my order and get what I wanted without all the fuss of waiting. I was looking for a waterproof light for the boat trailer, checked other sites, the internet, boat places, etc. couldn’t find what I liked. Then I remember etrailer I order new hubs from. They had what I was looking for. Should have called them first. Make sure and talk to Pat.
by:
THIS IS MY SOURCE FOR ALL MY AUTOMOTIVE LIGHTS!
I LIKE IT!
REFURBISHED MY CUSTUM TRAILOR WITH 10 LED RUNNING LIGHTS, 2 TWELVE INCH LED STOP/TURN/TAIL LIGHTS & OF COURSE THE LED TAG LIGHT.
ITS GORGEOUS!
THANX, E TRAILER .COM
by:
This trailer license plate light was exactly what I needed.
The order process was quick and easy and the light arrived within 5 days.
I am very pleased.
by:
Item purchased to replace another trailer license plate light. Perfect match. Very fast shipping.
by:
Ordered product on Sunday and received on Wed and finally got around to installing light on my boat trailer.Light was up to my expectation.Only time will tell if it is waterproof and stays up and running.
by:
Nice light, really wanted to get an LED light but this one is good quality. Make sure you check the bulb type. I was looking in the LED section and there are a few incandescent lights in this section.
by:
2018 Ford F-350 Super Duty
Not extremely bright, but worked OK on my trailer tag. Police are commonly pulling people over now days for not having a tag light.
by:
I needed 5 different kinds of lights for my boat trailer since they had all burnt out. Etrailer had all of them in stock. They were shipped out the same day I made the call. Three days later they were delivered. Steve Z helped out a lot with my phone order. They get 5 stars from me!!
by:
Perfect OEM replacement light and even came with an extra pigtail connector....I am very pleased with this light so far.
by:
etrailer had the light that no one else had... Ill be checking with them first on future items,, Thank You etrailer !!!
by:
Exactly what I wanted. Great price and quick shipping.
Highly recommend etrailer
by:
fashion. The delivery was exactly what I ordered. The light installed with ease. I have not trailered my boat yet but the light works and I expect it to be a great purchase.
by:
I've ordered a number of parts from etrailer over the years and everything came on time and was correct it's a joy to do business with them they're very good at getting the correct part the first time
by:
Quick shipping and great product.
by:
Best light I could find for the price. Mounted them in my boat for walkway lighting and tying on lures. Works great. Easy website to find what you're looking for and fast delivery. Will definitly use this business again. Thanks.
by:
Honda Odyssey
EXCELENT VERY GOOD USED FOR BOAT TRAILER TANKS AGAIN ETRAILER.COM
by:
Easy order, quick service. An exact replacement for my trailer. Thanks
by:
Your site was easy to search . I liked it. I like using pay pal and y'all take it. Thank you. The shipping was very fast aswell. I only use my iPhone to search an buy
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See what our Experts say about this Peterson Trailer Lights

Do you have a question about this Trailer Light?
  • Replacement Trailer Lights for 1999 ProCraft Boat Trailer
    We carry a broad range of trailer light replacement lenses as well as replacement lights and complete trailer lighting kits. The linked pages will display both license plate lights like # M439K and individual replacement parts like lens kit # W003372-73. You can sort the results shown by using the click-on filters on the pages. Usually the part number for a trailer light appears on the light base, rather than on the lens which usually displays only SAE/DOT info. I did find many photos...
    view full answer...
  • What to Do if the Peterson License Plate Light M439K Burns Out its Bulb
    So that it's watertight the Peterson Sealed, Trailer License Plate Light # M439K that you referenced is sonically welded. There is no way to replace the bulb. You would just have to replace the entire light.
    view full answer...
  • What Are Center To Center Dimensions Of Mounting Holes On Peterson Trailer License Plate Light
    The mounting holes on the Peterson Sealed, Trailer License Plate Light, part # M439K are 2-3/4-inches center-to-center. I have attached a photo of the light with the mounting dimensions noted. This light has a polycarbonate lens and is sonic welded for a watertight seal and also includes the wiring plug.
    view full answer...
    Image 1 for
  • Recommendation for License Plate Lamp to Shine Upward
    My best suggestion would be to use a bracket like the Steel Trailer License Plate Mount Bracket, # LP20SB, with the Peterson Sealed Trailer License Plate Light, # M439K, and mount the bracket upside down. This would give you a lamp below the license plate that would shine upwards. Before making a purchase, I do recommend contacting the Department of Transportation just to make sure that mounting a light that shines upward would not violate any of their regulations. Please also keep...
    view full answer...
  • Availability of LED-Version of Petersen License Plate Light # M439K
    Peterson does not offer an LED-type version of their incandescent License Plate Light # M439K but Optronics does offer their # LPL41CB, which is a Heavy Duty Trailer License Plate LED Light. This unit is also an ear-mount type, features a chrome-plated housing, 5 LEDs and a 2-wire hookup. I have linked a review video for your reference. The mounting hole spacing on the # M439K is 2-3/4-inches center-to-center. The mounting hole centers for the Optronics light are spaced at 3-1/4-inches....
    view full answer...
  • Availability of a License Plate Light that is Made in the U.S.A.
    I went out to the warehouse and pulled Peterson license plate light # M439K. The packaging does indicate that it is made in the USA. I have included a link to a video review of the light for you.
    view full answer...
  • Looking for a Trailer License Plate Light that is Submersible
    All of the license plate lights we have that are listed as submersible are incandescent, not LED. We have Peterson light # M439K and Optronics light # LP97CB. Though the lights are submersible you will need to make sure the wiring connections are water-tight by using something like liquid electrical tape, # SWC50122.
    view full answer...
  • Availability of LED License Plate Lights
    We do have some LED license plate lights. You could use # LPL31CB or # LPL41CB. I have included some links to video reviews for each of these lights for you.
    view full answer...
  • Power Connection of a Trailer License Plate Light on a 1997 Dodge 1500 Van
    The Peterson Sealed, Trailer License Plate Light, Ear Mount, part # M439K does not have a receptacle to plug into a cigarette lighter. You will need to splice the black wire from the back of the light into the Dodge Van running light circuit behind one of the the vehicle taillights, so that it will illuminate whenever the running lights are on. The white wire will need to be connected to good ground point.
    view full answer...
  • What is the Difference Between M439 and M439K Trailer License Plate Lights
    The Peterson Sealed, Trailer License Plate Light, Ear Mount, # M439K, comes with a mounting bracket. I could not bring up the M439. But according to the manufacturer M439 does not come with a mounting bracket. For a license plate light, you might also be interested in Heavy-Duty, LED Trailer License-Plate Light with Mounting Bracket, # LPL55CB. This light comes with a mounting bracket.
    view full answer...

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Info for this part was:

Employee Robert G
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Employee Adam R
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Employee Jeffrey L
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Employee Cole B
Installed by:
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Updated by:
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Employee Brian T
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