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Grommet for ST33 Series Tall Rectangle Flush Mount Trailer Lights

Grommet for ST33 Series Tall Rectangle Flush Mount Trailer Lights

Item # A33GB
Our Price: $4.71
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Shipping Weight: 0.28 lbs
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A33GB - Grommet Optronics Trailer Lights
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Optronics Accessories and Parts - A33GB

  • Trailer Lights
  • Mounting Hardware
  • Grommet
  • Rectangle
  • Optronics
  • 6-1/4 Inch Long

Grommet for ST33 Series Tall Rectangle, Flush Mount Trailer Lights

A rectangular, black PVC grommet with rounded corners needed for flush mounting ST33 and STL33 Series lights. This open-backed grommet measures 6-1/4" long x 4-3/8" wide x 1-11/16" deep. The rubber grommet gives shock mount protection that extends the life of the lamp. The open back allows access for the necessary wiring. Along with the sealed light, a three-wire pigtail is required to complete the installation.

  • Rubber grommet for flush mounting ST33 Series lights
  • Shock protection extends lamp life
  • Open back gives easy access for wiring
  • Requires a three-wire plug (A45PB or A47PB) along with the light to complete installation
  • Dimensions: 6-1/4" L x 4-3/8" W x 1-11/16" D

Manufacturer Cross Reference
Grommet will work as an exact replacement for:
Uni Bond # GR4060

Manufacturer Specifications

Black PVC grommet allows flush mount of ST33 and STL33 Series lights. Provides shock mount to length lamp life.

dimensions of grommet

A33GB Grommet for ST33 and STL33 Series by Optronics, Inc.

Alternate part number: A-33GB

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Grommet for ST33 Series Tall Rectangle Flush Mount Trailer Lights - A33GB

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


Vicky was very profrational very helpful I wish more people were like her in this world it would make this world go round and round a lot easier. Thanks for everything ya'll looking forward to putting them on my trailer


Great service! Parts ordered arrived in record time, order was complete, and no problems. I had ordered same parts from another supplier, waited 5 weeks and when order arrived it only had one light not two as were ordered. Still having issues trying to get that order resolved. You guys make it easy, will get more orders from me as well as letting my friends know where to order from. Thanks


The lights I ordered came promptly with no problems. I expect to install them on a small ag tractor where flush mount is a must ! Although not installed yet they appear perfect for the intended use . Thanks it was hard to find the size i needed elsewhere.

Excellent no issues very well pleased
mike - 01/06/2019


I have a flat bed on my truck and it uses trailer lights in it. When I looked for replacements all the stores wanted $10 to $30 a peace!!! Etrailer saved me almost $100 over going to may local store. I ordered it on sunday night. I had 2 personal emails telling me my order was ready and being shipped. ON SUNDAY NIGHT!!! I had my order by Wednesday with a follow up email telling me my package was waiting for me at home. My only complaint is why other online stores can provide this service. etrailer, I will be ordering again. Thank You


I had discontinued Command 003-5900 lamps on my trailer and these worked great. I ordered the grommet and 90 degree pigtail as well which together made it work. They are nice and bright and work as expected. Purchasing and delivery all were 100%. Exceeded my expectations.


Perfect fit, good price, fast shipping


Grommets were as expected, customer service was above and beyond..nowhere else have receive do much communication..keep up the good work -let me know when you open a restaurant ? :)


Bit of stiff vinyl feel, not as flexible as the usual oval 6 inch grommets, but looks good, no mold flash, good price for what it is.


I have ordered from etrailer many time with great success.


Fit the C & M Truck Bed perfectly


Got the lights on time very bright would recommend them to anyone


Product was as pictured. Received in a timely manner.




Great price fast shipping very pleased


Worked great






See what our Experts say about this Optronics Accessories and Parts

  • Is there a Mounting Bracket for Trailer Back Up Light # BU33CB
    There is no bracket for external mounting of grommet # A33GB so you will have to cut a hole where you want the grommet and light to go. Use the grommet as a template to cut the hole. Start small because you can always work your way up to a larger hole if needed.
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  • What Size Hole is Needed to Mount the Optronics Tail Light # ST33RB
    With the Tail Light, # ST33RB, inside of the appropriate grommet, # A33GB, you would need a hole that is approximately 5-7/16 x 3-3/4 inches. You will also need the appropriate wiring harness, # A45PB.
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  • Dimensions and Mounting Grommet Recommendation for the LED Back Up Light part # BUL35CB
    I attached a picture of the LED Back Up Light part # BUL35CB that shows its dimensions. If you were planning on making a grommet to install these lights you could instead just get the Grommet part # A33GB as this grommet is specifically designed to fit this light.
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  • Can Custer 4-LED Strobe Light or Running Light Be Used As A Back Up Light On 2001 28 ft class C RV
    I would encourage installing a light that is intended to be a backup light on your motorhome. You may want to check out part # BUL35CB. This is a 16-diode LED light that is certified as a back-up light when installed as a pair. This light also requires a grommet, part # A33GB, and a 2-wire pigtail, part # A45CB. The Custer 4-LED Strobe Light or Running Light, part # STRL4A is actually designed to be a running light or a strobe light. You could attach it to the reverse light circuit on...
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  • Can the RV Porch and Utility Light be Used on a Camper Shell for Side Illumination for Sled Dogs
    The RV Porch and Utility Light, # RVPL3C, would definitely be able to handle normal highway speeds, if mounted correctly, but a car wash might be a different story. These lights were designed for RVs and they are not normally ran through car washes. If the car wash were a touch-less model then you should be fine, but a car wash with the mops that twirl would most likely cause an issue with the lights protruding from the side of the shell. Another option may be to install a flush mounted...
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  • Is LED Backup Light BUL35CB Much Brighter Than Incandescent BU33CRXLB
    The difference between the lights isn't in the brightness so much as the clarity, so the Optronics LED Backup Light for Truck or Trailer # BUL35CB is not significantly brighter overall than the Backup Light with Red Reflex Reflector # BU33CRXLB. I have added some photos showing the lights on for some reference, though keep in mind it's not a perfect representation due to camera angle, room darkness, etc. but I wanted to show an example of the different kind of light. In regards to the...
    view full answer...
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  • Will Right Angle Pigtail Fit With STL33RB Optronics LED Trailer Tail Light
    Yes, the Optronics LED Trailer Tail Light # STL33RB will pair up directly to the Right Angle 3-Wire Pigtail # A47PB. To complete your install you may also want to pick up the Grommet # A33GB and Butt Connectors # DW05743-5. Attached are some videos for you to check out.
    view full answer...
  • LED Trailer Tail Light Recommendations for a Boat Trailer
    The Sealed, Miro-Flex, Thin Line, LED Lights, # MCL63CRB, are DOT approved as Trailer Marker, Clearance or ID Lights only, so you would not be able to use them as tail lights. A similar light in shape and size that would work for you is the Miro-Flex, Waterproof, Rectangular, LED Trailer Light, # STL33RB. You would also need a wiring harness like # A45PB, and a grommet, # A33GB. Or, if a rounded light is acceptable, you can go with # STL70RB, with wiring # A45PB and Grommet # a70gb.
    view full answer...
  • What Size Hole is Needed to Mount the Optronics Tail Light # STL35RB
    With the Tail Light, # STL35RB, inside of the appropriate grommet, # A33GB, you would need a hole that is approximately 5-7/16 x 3-3/4 inches. You will also need the appropriate wiring harness, # A45PB.
    view full answer...
  • Can Optronics LED Backup Light # BUL35CB Be Mounted Horizontally
    The Optronics Flush Mount LED Backup Light you referenced, part # BUL35CB can indeed be mounted onto the deck of a car trailer. The lamp is sealed, so you will have no worries about water entering the lamp housing. You would also need a grommet, part # A33GB and the wiring pigtail, part # A45CB.
    view full answer...
  • Recommendations for installing a LED Trailer Light # STL35RB on a 2002 Ranger Trail Trailer
    This Miro-Flex, Waterproof, Rectangular, LED Trailer Stop/Turn/Tail Light # STL35RB that you referenced should work well with your trailer wiring. You will need a Straight 3-Wire Pigtail # A45PB to wire it into your trailer wiring. The red wire from this harness will run to the turn signal circuit, the black is the tail signal, and the white will ground to the trailer frame on a clean metal surface to complete the circuit. You might also be interested in purchasing a Grommet for ST33...
    view full answer...
  • What are the Dimensions of Optronics Flush Mount LED Backup Light BUL35CB
    The LED backup light # BUL35CB is 5-5/16 inches long x 3-7/16 inches wide x 2-5/16 inches deep. You will also need a wiring pigtail, # A45CB to install this light. For a grommet, use # A33GB. I have included a picture showing the light dimensions for you.
    view full answer...
    Image 1 for
  • Depth Dimension of Optronics Miro-Flex LED Trailer Stop/Turn/Tail Light STL35RB
    The actual depth of the Optronics Miro-Flex LED Trailer Stop/Turn/Tail Light # STL35RB is 2-5/16-inches, as shown in the linked diagram which includes overall dimensions too, but you will also need to allow for the right-angle plug # A47PB which will add another inch. This light is intended for installation using rubber grommet # A33GB.
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  • Available Flush Mounted Tail Lights for Camper
    We have many flush mount taillights to choose from. If you click on the provided link, you can see our selection. We have a few lamps that are similar in size to the Wesbar lamp you mentioned. The Optronics Flush Mount Rectangular Tail Light, part # ST33RB measures 5-5/16 by 3-7/16 inches. It uses a grommet mount, sold separately as part # A33GB and would require a pigtail, part # A45PB. The same lamp is available in a LED version, part # STL33RB which would use the same grommet and pigtail. Optronics...
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  • What Size Hole Is Needed to Install the Flush Mount Rectangle Light and Grommet
    The Rectangle LED Trailer Stop, Turn and Tail Light, # STL34RB, needs a hole that is 3-3/4 inches by 5-3/8 inches. This light comes with the grommet and the 3 wire pigtail for installation. There is also a right angle pigtail available, # A47PB, if space is limited behind the mounting location for the light. For a really clean looking installation you will want to radius the corners to match the corners of the grommet. I would draw a 3-3/4 x5-3/8 inch square on a piece of paper or cardboard...
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  • Can the Miro-Flex LED Trailer Light be Mounted Vertically and Horizontally
    As long as you have adequate room to mount the Miro-Flex, Waterproof, Rectangular, LED Trailer Stop/Turn/Tail Light # STL35RB you could mount it in basically any orientation you like. You might also be interested in purchasing a Right Angle 3-Wire Pigtail # A47PB or a Straight 3-Wire Pigtail # A45PB depending on your mounting location. Or a Grommet # A33GB for mounting.
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  • Are Load Resistors Needed for Reverse LED Trailer Lights
    You will not need load resistors to install the Optronics LED Backup Light for Truck or Trailer # BUL35CB; load resistors are not needed for reverse lights like these. The only thing you will need are Grommet # A33GB and a 2-wire pigtail, either part # A45CB or the right-angle pigtail, part # A49PB. I have added links for video reviews for you to check out as well.
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  • Grommet and Pigtail Needed for the Optronics Miro-Flex # STL35RB Trailer Light
    The grommet that you will want to use to install the Optronics Miro-Flex # STL35RB is the Optronics part # A33GB. For a pigtail you have 2 different options. The 3-Wire Pigtail for Optronics Trailer Lights part # A45PB has a straight connector and the Right Angle 3-Wire Pigtail for Optronics Trailer Lights part # A47PB has a right angled connector.
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  • Availability of White LED-Type Rectangular Backup Light
    For a rectangular white LED-type backup light I suggest the Optronics Flush Mount LED Backup Light # BUL35CB. This recessed-mount light uses an industry-standard plug like # A45CB and a mounting grommet # A33GB. Please click on the video link for more.
    view full answer...
  • Amber Trailer Blinker/Running Light Recommendation for Use on an Older Truck
    We don't have exactly what you said you need, but the closest thing we have would be the Miro-Flex, Waterproof, Rectangular, LED # STL35AB. This is an LED amber light you could use that has dual intensity so that it can be used for a blinker and running lights. Only thing is that this is much bigger at 5-5/16" L x 3-7/16" W x 2-5/16 D. For a harness to plug into the light you would want # A47PB and then for a grommet part # A33GB.
    view full answer...
    Image 1 for
  • Recommended Parts to Install Optronics Flush-Mount Clear LED Trailer Backup Light # BUL35CB
    The Optronics Flush-Mount Clear LED Trailer Backup Light # BUL35CB that you referenced uses a tiny amount of power since it features high-efficiency LEDs instead of standard incandescent bulbs. Its power draw is about 1/10th that of standard bulbs, approximately 0.295-amps at 12.8 volts. This light uses a standard 2-prong connector that accepts wiring pigtail # A45CB. It mounts with grommet # A33GB. To use this as a backup light you will need to connect it to your Wrangler's reverse light...
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  • Running Lamp Circuit on Thule TH665C Transporter Combi Cargo Carrier Not Working
    The taillights on the Thule # TH665C Transporter Cargo Carrier should function as brake lamps. turn signals and running lamps. It sounds like you have a problem with the running lamp circuit, as the license plate lamp is on the same circuit. I'd first test the trailer connector on the vehicle while the headlights are on. A simple circuit tester like # PTW2993 works well for this. Check the pin on the connector that's fed by the brown wire. If you're not getting power on that wire with...
    view full answer...

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Info for this part was:

Employee Michael H
Expert Research:
Michael H
Employee Laura H
Updated by:
Laura H
Employee Brian T
Updated by:
Brian T
Employee Noah M
Updated by:
Noah M

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