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Rubber Grommet for 4" Round Trailer Lights - PVC

Rubber Grommet for 4" Round Trailer Lights - PVC

Item # A45GB
Our Price: $5.44
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Shipping Weight: 0.2 lbs
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This black PVC grommet allows you to flush mount your Optronics 4" round trailer light. Shock mount protection extends the life of the lamp. Recessed mount. Durable plastic construction. 1-800-940-8924 to order Optronics accessories and parts part number A45GB or order online at Free expert support on all Optronics products. Great prices and Fastest Shipping for Rubber Grommet for 4" Round Trailer Lights - PVC. Accessories and Parts reviews from real customers.
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Optronics Accessories and Parts - A45GB

  • Trailer Lights
  • Mounting Hardware
  • Grommet
  • Round
  • Optronics
  • 4 Inch Diameter

This black PVC grommet allows you to flush mount your Optronics 4" round trailer light. Shock mount protection extends the life of the lamp. Recessed mount. Durable plastic construction.


  • Grommet allows you to flush mount your Optronics 4" round trailer light
    • Designed to fit Optronics 45 Series lights (sold separately)
  • Shock mount design cushions light against vibration and jolting
  • Open back provides easy access when wiring
  • Light snaps into grommet for a finished look
  • Durable PVC construction
  • Recessed mount installation - hardware not included
    • Requires 4-1/2" cutout


  • Outer diameter: 5-3/8"
  • Mounting depth: 1-1/16"

Optronics PVC grommet for 4 Inch Round Flush Mount Lights Diagram

Manufacturer Cross-Reference

Grommet will work as an exact replacement for:

  • Uni Bond GR4000
  • Wesbar 224088
  • Truck Lite 40700
  • Grote 91740
  • Peterson 426-18
  • Bargman 40-01-020

A45GB Optronics Rubber Grommet for 4" Round Sealed Trailer Tail Lights - Recessed Mount

Alternate part number: A-45GB

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Rubber Grommet for 4" Round Trailer Lights - PVC - A45GB

Average Customer Rating:  4.7 out of 5 stars   (187 Customer Reviews)

This black PVC grommet allows you to flush mount your Optronics 4" round trailer light. Shock mount protection extends the life of the lamp. Recessed mount. Durable plastic construction.


These are good grommets for the price. I've purchased a few over the years and they have never failed. I've only replaced them because they got some over spray from paint on them or something like that and it's cheaper and easier just to buy another pair and have them look brand new again. I use them on a Jeep built for rock crawling and I've attached a picture of one of them on the Jeep but this is an old set and not the best picture but you get the idea. They hold up well to abuse.

Matt F.


Still working well and holding up to the punishment I put them through.


super tight fit. used a little lube to install. no cracking or deterioration as of 1 year


Heavy duty grommets


Worked as it should.


Restoring a 1991 2 horse trailer. etrailer had all the exact lights made by Peterson, 35 years later.


Product as described. Service and communication excellent.


The grommets did not fit into my original openings. I had to use a die-grinder to enlarge the holes by 1/8” all the way around. Once complete, they fit pretty good.


I ordered the STL101RB Trailer Tail Light - Stop, Tail, Turn, Backup - LED to replace the standard tail lights on my Yamah Drive G19 golf cart. They replaced to stock ones perfectly as a neat way to add a backup lights for a custom feature. The backups led are actuated by the reverse switch on the dash.

It should be noted that the ground terminal on the two wire pigtail connection is not wired internally to the backup LEDs. They rely on the ground supplied by the three wire pigtail. Not a big deal, but worth noting. It throws a curve when bench testing.

These lamps add a nice custom touch!


Product was delivered on time and meets my expectations for quality. I would buy this again and from eTrailer because of their service.


Items arrived as described. Good quality, price and fast delivery made this purchase an overall great deal. The lights, cables and grommets I haven’t test them, waiting for my truck replacement bumper to arrive in September and have the body shop install them for me. I will update my review, but for now I recommend this products and the seller.



After a year using this product function-ability still performing as described. I recommend this product and seller.


Very pleased now other drivers can see my tail lights. Better yet turn signals & stop lights are bright .I would recommend these lights to any drivers that want to be safe on the highways

Roger R.


Very well I should have ordered these years ago.


Hi guys,
I'm usually the one answering
These guys are great! My client emailed the link & told me to order these for our horse trailers.
They've held up, to the point, we're not even close to needing to replace them.
We haul quite a bit. These lights have been tried & true, day & night.
When you're hauling a lot of livestock, you want people that have no clue what that entails, to see your lights well before they get near your livestock ; these lights do the job perfect!
We've outfitted 3 separate trailers with this company. We restored wires, lights, & pretty much everything along those lines ;from a 2 horse, to a large stock, & a gooseneck. All the parts come quickly, are all there, & work & fit great. What more can you ask for?!


I have been looking for a long time to find a replacement for this light.
I could buy others, or kits etc, but I wanted this same light.
I contacted the company and explained what I needed.
They had it in stock as well as sealed light, the wires and connections.
It was delivered Very promptly, within a matter of days.
Excellent service.

Trailer L.


Actually, It came out of the rubber gasket when we put the boat into the water====Never found it!


The amber led lights I received were great and I installed them in the front of my 2002 Pontiac Firebird cuz I clipped another deer and ran over a raccoon in the same night and they took out my front lights again. So, rather than try to purchase an original set of turn signal and fog light assemblies along with the expensive bulbs, I converted it over to led and it is a great upgrade for an older car. The problem is that the three color coded wires came with no directions that told me which wire was ground, park, or turn. I had to figure it out as the color codes are different on my car. I would send a pic, but it is on my cellphone.


The rubber grommets are fine just a little tight for my existing lights to fit in. I had to use some glass cleaner to get them to even have a chance of going in and a lot of brute force. Now I'm not sure if it is because they weren't matched with the LED's I already have or maybe the rubber is not so "rubbery" I've had issues with other "rubber" things. All in all they replaced the cracking existing grommets and they look good.
The 2" marker lights were a waste of money not because there are issues, but because I needed 2 1/2" ones so these don't fit. I ordered wrong, but the quality of the lights look good.


I ordered a set of tail lights for my boat trailer and they shipped fast. The customer service is really great too. The product is high quality and I'm very happy with it. The only issue I had with is they charge far too much for shipping and they only use UPS. So people like me who have a frequent shipper contract with other freight and delivery companies can't get it shipped at a reasonable cost. It is unreasonable to me to pay just as much for shipping as the product cost. Etrailer if you are listening, please ship small things in USPS flat rate boxes and allow customers to use their frequent shipping agreements with other delivery services.


I’ve used etrailer on multiple occasions and have been completely satisfied with their service and professionalism .



Superb. I thank you for the service and professionalism that the company exhibited.


Perfect for what I needed - seals for computer cable access in a desk...timely delivery...excellent!


The product arrived quickly and was just as described. My trailer is older and I was having trouble finding replacements for the tail lights. Their sales rep, Cathy T., was knowledgeable and friendly. The next time I need parts for my horse trailer, I will go directly to etrailer.


Here's the pic of my finished project. Thanks for ur help.


extremely quick delivery. excellent service rep. AAA+


Communication with etrailer has been really good.This item was back ordered and they let us know immediately.

The grommets fit well into the holes and the lights pop in snuggly.


Working well the trailer is parked out in the weather all year and the grommets are not hard of cracking


etrailer as always has what I need, ships fast, and product is "as advertised"!
A pleasure to talk to the tech's when I have questions and even go as far as calling manufacturer to verify equipment selections.
Keep up the GREAT work.


I fought with these PVC grommets for 10 minutes then gave up. Waaay to stiff. I'm going to stick with rubber grommets and change them out when they start cracking and shrinking.

Show More Reviews

See what our Experts say about this Optronics Accessories and Parts

  • What Size Hole is Required to Install Optronics Grommet A45GB
    The grommet part # A45GB that you referenced requires a 4-1/2 inch diameter hole be cut to install. I looked up the light you mentioned and it is a 4 inch diameter light like what this is designed to fit. I attached an install video for you to check out as well.
    view full answer...
  • Size Hole Needed to Install 4 inch Trailer Taillight that is Flush Mounted
    When used with the # A45GB grommet, a 4-1/2 inch diameter hole is needed to flush-mount a 4 inch taillight.
    view full answer...
  • Dimension of Thickness for Optronics Rubber Mounting Ring A45GB
    The Optronics rubber mounting ring # A45GB will fit into the hole that is 4-1/2 inches round, but the thickness of the mounting ring is 1-1/16 inches in depth. So if your plywood panel accommodates this amount of depth, then this rubber mounting ring will work well for you.
    view full answer...
  • What is the Minimum Thickness of the Surface that Rubber Grommet A45GB Can Be Mounted To
    Rubber grommet # A45GB is 1-1/16 inches deep but the material you are mounting the light in does not have to be that thick. A minimum 3/16 inch should be sufficient. Metal (aluminum or steel) would be the preferred surface. Fiberglass and other similar materials can flex much easier which could result in the light popping out of the hole. But this is not likely if the hole is cut to the proper size (4-1/2 inch diameter).
    view full answer...
  • Difference Between Grommets # A45GB and # A45GNB
    The difference is that the grommet part # A45GNB has a notch cut in the lower portion that seals to the mounting hole. This allows the grommet to install a bit easier than the part # A45GB.
    view full answer...
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  • How Thick Of a Plate Will the Optronics Rubber Grommet for 4 Inch Round Lights Fit
    I went out to our warehouse to measure the seat of the # A45GB grommet that you referenced. It seems like it will be a tight fit for your 3/8 inch bumper. The grommet seat measures 0.24 inches. Another option for mounting a 4 inch round light on your trailer, instead of the bumper, is to use the Trailer Light Mounting Bracket # BK45BB. This may not work for your application, but it could also be modified to work how you need. This bracket will work well with the rubber grommet # A45GB.
    view full answer...
  • How Does the Chrome Cover # A45CGB Install Over Rubber Grommets
    I spoke with my contact at Optronics and she said you will need the 4" grommet, part # A45GB, to flush mount your 4" lights. The grommet gives shock mount protection that will extend the life of your lamp. The chrome cover, part # A45CGB, is designed to be screwed into the grommet part by the two screws which are included. The 4" grommet requires a 4-1/2 inch diameter mounting hole. You may also need a wiring harness like # A47PB.
    view full answer...
  • Do You Carry the Wire Pigtails and Grommets Needed to Install Optronics 4 Inch LED Light STL53AB
    The grommet for the Sealed 4 Inch LED Light you were looking at is part # A45GB. The outer diameter is 5-3/8 inches. It is designed to use used in a 4-1/2 inch cutout or hole. The 3 wire pigtail is either part # A47PB or part # A45PB depending on style needed.
    view full answer...
  • Fog Lamps for Aftermarket Bumper on 2007 Toyota FJ Cruiser
    If the hole in your bumper is actually slightly larger than 4 inches in diameter, I have what might be the perfect solution for you. The Rampage Fog Lamp Kit, part # RA5083059 is specifically designed to be mounted into a Rampage aftermarket bumper. You didn't mention who manufactured your bumper, but I believe this product would be the closest thing we offer to what you're looking for. The lamp is Halogen, and would sit in opening of your bumper, but it would not mount with a grommet....
    view full answer...
  • Can Peterson Round Flush Mount Trailer Light be Installed in 1/8 Inch Thick Diamond Plate
    Yes you can install red flush mount light # 435800 in diamond plate. The grommet will hold the light in place by compression. For a similar backup light you can use # BU45CB with grommet # A45GB and wiring harness # A45CB.
    view full answer...
  • LED Utility Light Recommendation in White for Cabinet Light of Ambulance
    The best solution is going to be with a larger size light if you can enlarge the hole you have like with the Optronics LED Backup Light for Trucks or Trailers # BUL11CB and grommet part # A45GB. You'll need to cut the hole out to 4-1/2 inches in diameter but you'll get a really bright LED setup that will work great. You'll also need a pig tail harness as well with part # A45CB. We don't have anything that would fit a 2-1/2 inch diameter hole.
    view full answer...
  • Wire Pigtail for Optronics 4 Inch Round LED Trailer Reverse Light
    Although the rear of the lamp features three pins, only two of them are active which is why the 2-prong pigtail is called for (see photo). My guess is rather than design a separate back for lights that only need the 2 pin pigtail, Optronics finds it more cost effective to use a single back for all their 4 inch round lights.
    view full answer...
    Image 1 for
  • Recommended Grommet for Optronics 4 Inch Round LED Light # STL55RB
    Both the Rubber Grommet # A45GB and the Notched Rubber Grommet # A45GNB that you referenced will fit and work well with the Optronics 4" Round LED Light # STL55RB. The only difference between the two grommets, as you mentioned, is the notched cut out in the lower portion of the unit. This is not necessary for wiring or fitment, but it will allow for a bit of an easier install.
    view full answer...
  • Are LED Lights with More Diodes Brighter and Can a Trailer Backup Light be Used on a Truck
    It is pretty safe to assume that the more diodes in an LED light the brighter it will be. The only time that is not necessarily true is if one light has large diodes and the other doesn't. But any way you slice it light # BUL53CB and its 36 diodes is going to be bright. In this case, for all intents and purposes, a 4-5/16 inch and 4-1/4 inch diameter won't make a difference. The light can be used on your truck. In fact a lot of people use lights like this and other trailer lights on...
    view full answer...
  • What is Included with Optronics 4 Inch Round LED Tail Light
    The Optronics 4 Inch Round LED Tail Light # STL43RB does not come with a pigtail. For a 3-Wire Pigtail with a 3-Prong Plug # A45PB is what you'll need. If you'd like the rubber grommet then # A45GB is what you're looking for.
    view full answer...
  • Is the Optronics LED # STL43RB the Correct Replacement for Peterson 426 Taillight
    The Optronics LED Taillight you referred to, part # STL43RB would indeed be a correct replacement for the Peterson 426 lamp you referred to. The # A45GB would be the correct replacement grommet and for a pigtail, you'd use part # A45PB. The LED replacement would be a great option, as they use a lot less power, would last much longer and are quite a bit brighter than their incandescent counterparts.
    view full answer...
  • Wiring and Mount for Optronics 4 Inch Round Trailer Light # ST45RB
    Sealed, 4" Round Trailer Stop, Turn and Tail Light, Flush Mount, 3-Function Item # ST45RB has a plug in the back to accept pigtail # A45PB. On it the white wire is ground, black is for tail lights, and red is for brake lights and turn signals. This light can be mounted using grommet # A45GB with bracket # BK45BB. Or if mounting directly in a surface you would just need the grommet. I have linked videos of all of these parts for you.
    view full answer...
  • Replacement LED Trailer Tail Lights for a 2005 Gulfstream BT Cruiser
    Optronics trailer tail light # ST45RB is potentially a fit for your trailer if the existing lights are one of the following: Uni Bond # SE4000R Wesbar # 423541 Truck Lite # 40282R/40202R Grote # 52922 Peterson # 426R Bargman # 40-01-001 This information is likely on the light housing somewhere on your existing lights. The 2 knobs on the back are not an issue since this light would mount in a hole in the trailer or in mounting bracket # BK45BB both using grommet # A45GB. If you are not...
    view full answer...
  • Parts Needed to Install 4-1/2 inch Diameter Light in Trailer
    Yes, all three of the parts you mentioned are what's needed to install a light assembly in a 4-1/2 inch diameter hole. The light part # ST45RB fits the # A45GB, and the pig tail part # A4PB is the correct one as well.
    view full answer...
  • How Does Trailer Light # ST45RB Mount into Mounting Bracket # BK45BB
    I went out to the warehouse and pulled Optronics Trailer Light, # ST45RB. First, you will need to place the Rubber Grommet, # A45GB, into the mounting bracket, # BK45BB. Next, you will need to press the light until it is seated all the way in the bracket. This last step actually takes some strength as the light is held in place by the grommet. I had to use some lubricate to get the light to seat all the way in the mounting bracket. Once in place, the light will not come out unless it is...
    view full answer...
  • Is Peterson Red Round Replacement Lens # 420-15 Interchangeable with DZ 77-845 Tail Light
    The Peterson Red Round Replacement Lens, # 420-15, is not interchangeable with the DZ 77-845 light that you referenced but I may have a solution. For just a bit more than the cost of a lens, you could replace the entire light assembly with the Sealed, 4" Round Trailer Stop, Turn and Tail Light, # ST45RB. 3-Wire Pigtail, # A45PB, and Rubber Grommet, # A45GB, would be needed in addition to the light. Unfortunately we do not offer a replacement lens that will work for your current light.
    view full answer...
  • What is the Brightest 12 Volt Fully Submersible Backup Light Available
    If you are looking for a round backup light then I recommend part # BUL53CB but if you are looking for an oval backup light then I recommend part # BUL52CB. Both of these backup lights are completely submersible. The round light has 36 diodes with a 275 candella rating and the oval light has 36 diodes with a 175 candella rating therefore the round light will be a bit brighter than the oval light. In order to mount the round light you will also need part # A45GB or part # A70GB for the...
    view full answer...
  • Glo Light Trailer Tail Light Installation With Grommet
    You will install the GloLight LED Trailer Tail Light - Stop,Turn,Tail - Submersible - 21 Diodes - Round - Red Lens # STL101RB after you install the grommet # A45GB in the bumper first. This ensures the mount is in place correctly and the light will then hold firmly in place.
    view full answer...
  • Does Fusion GloLight Tail Light part # OPT64WR Require Resistor
    Since the Fusion GloLight Tail Light part # OPT64WR is designed to be a trailer light and not a vehicle light it does not have any resistors integrated into it. Trailer wiring does not require this because the signal comes from the vehicle wiring which already has the flasher unit functioning. If the light was to be installed on a vehicle in place of a blinker circuit a resistor would be needed or a digital flasher installed on the vehicle instead of a thermal unit. The proper resistor...
    view full answer...

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