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Optronics Trailer Tail Light - Stop, Turn, Tail - Round - Grey Flange - Red Lens

Optronics Trailer Tail Light - Stop, Turn, Tail - Round - Grey Flange - Red Lens

Item # ST47RB
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Optronics Trailer Lights - ST47RB
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5-1/2" Diameter round. Waterproof, incandescent trailer light serves 3 functions: stop, turn, and tail. Shock-proof socket protects bulb. Surface mount with built-in flange. Accepts standard 3-prong plug. 1 bulb. Lowest Prices for the best trailer lights from Optronics. Optronics Trailer Tail Light - Stop, Turn, Tail - Round - Grey Flange - Red Lens part number ST47RB can be ordered online at etrailer.com or call 800-298-8924 for expert service.
  • All Info
  • Reviews (4)
  • Q & A (5)
  • Videos (1)
  • Photos
  • Why etrailer?

Optronics Trailer Lights - ST47RB

  • Tail Lights
  • Round
  • Incandescent Light
  • Red
  • Recessed Mount
  • 4 Inch Diameter
  • Optronics
  • Submersible Lights
  • Stop/Turn/Tail

5-1/2" Diameter round. Waterproof, incandescent trailer light serves 3 functions: stop, turn, and tail. Shock-proof socket protects bulb. Surface mount with built-in flange. Accepts standard 3-prong plug. 1 bulb.


  • Red, round incandescent trailer light serves 3 functions
    • Stop, turn, and tail
  • Sealed, waterproof housing and lens unit
  • Incandescent bulb is easy to replace
  • Shock-proof socket protects bulb against damage
  • Red lens over incandescent bulb
  • Compatible with 12V DC systems
  • Surface mount to trailer with built-in flange - hardware not included
  • Accepts industry standard 3-prong plug (A45PB - sold separately)


  • Dimensions: 5-1/2" diameter x 2" thick
  • Distance between mounting holes (center on center): 4-1/4"
  • Bulb type: incandescent
  • 3-Year warranty

Manufacturer Cross Reference
Light will work as an exact replacement for:
Truck Lite # 40229R
Peterson # M424R

Optronics ST47 Series Trailer Tail Light Dimensions

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 circuit board is sealed, which means that water will not damage the diodes or circuit board.

ST47RB Optronics Incandescent Trailer Tail Light w/ Mounting Flange - Submersible - Stop, Turn, Tail - Round - Grey Flange - Red Lens

Alternate part number: ST-47RB

California residents: click here

Video of Optronics Trailer Tail Light - Stop, Turn, Tail - Round - Grey Flange - Red Lens

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

Video Transcript for Optronics Trailer Lights - Tail Lights - ST47RB Review

Today, we're going to be reviewing Part Number ST47RB. This is the Optronics Sealed, 4" Round Trailer Light. The red, round trailer light is going to serve three functions such as your stop, turn, and tail light functions. It's going to feature a sealed, waterproof housing and lens unit. It's also going to feature a heavy-duty, long-life bulb. It is an incandescent bulb that sits in a shockproof socket, so it is going to guarantee a long bulb life. You see here around the perimeter of the light, it's got a nice flange mount that's going to mount through the three holes in the housing.

If we take a measurement, center on center, the distance between the holes, it's going to give us a measurement of 4-1/4". Here on the back of the housing, you're going to see that it will accept your industry-standard, 3-prong plug. These are going to be sold separately. You can find them right here, etrailer.com, using Part Number A45PB, that's going to be the Straight 3-Wire Plug, or you can use Part Number A47PB, that's going to be the Right Angle 3-Wire Plug. Going over the overall dimensions real quick, it's going to give us a diameter, measuring from outside edge to outside edge, of 5-1/2", and it's going to give us an overall depth of right at 2". We're going to go and connect it to our external power source.

That way, you can see what it looks like with power running to it, and then with our overhead lights turned off. All we need to do is plug in a 3-wire plug here on the back side of the housing. Once we get that plugged in, we can simply prepare to turn on our power source, and then we can turn off our overhead lights. Here, you can see that it's going to send out a nice, consistent signal. This is going to be for the tail light function, and then when we apply the break switch, you can see how that illuminates for an even brighter signal, also functioning as our turn signal as well. That's going to do it for today's review of Part Number ST47RB.

This is the Sealed, 4" Round Trailer Light from Optronics. .

Customer Reviews

Optronics Trailer Tail Light - Stop, Turn, Tail - Round - Grey Flange - Red Lens - ST47RB

Average Customer Rating:  5.0 out of 5 stars   (4 Customer Reviews)

5-1/2" Diameter round. Waterproof, incandescent trailer light serves 3 functions: stop, turn, and tail. Shock-proof socket protects bulb. Surface mount with built-in flange. Accepts standard 3-prong plug. 1 bulb.

- ST47RB

Good for Union Pacific shipping container chassis. Need 3/16 rivets 501951

- ST47RB

This light was easy to install and works great. 210094

- ST47RB

Everything was as described. Fast shipp ing. 126267

- ST47RB

Just what i throught it would be. Than ks 14387


Ask the Experts about this Optronics Trailer Lights

  • Testing LED Trailer Lights Using an External 12 Volt Power Source
    You should be able to ground the white wire and apply 12 volt power to one of the other wires and get the light to illuminate. If the ground is not sufficient, the lights will not light up. If the power source is not putting out 12 volts or requires a certain amount of load before it will allow power through the lights might not work. The back of the light housing normally indicates the function of each wire. One method you can try is to use a car battery, attach the ground wire to the...
    view full answer...
  • Left Side Trailer Lights Not Working on Multiple Trailers Being Towed By 2007 Ford F-150
    On your 2007 Ford F-150 I would start by checking the relay fuse box located under the right hand side of the instrument panel inside the cab. There are two 10 amp fuses in the box that protect the trailer towing lights. The fuse at location number 36 is for the right side lights and the fuse at location number 42 is for the left side lights. I would also recommend to check your owners manual to determine if you are missing any other fuses or relays that are required for towing a trailer....
    view full answer...
  • Hole Size Needed to Install the Optronics Sealed 4 Inch Round Trailer Light # ST47RB
    I pulled the Optronics Sealed 4 Inch Round Trailer Light, # ST47RB, from the warehouse and measured the diameter of the light housing that will be recessed in the trailer. It measures 4.44 inches in diameter so a 4-1/2 inch hole should be fine. I spoke with my contact at Optronics and they do not recommend a specific hole diameter for this light, but most flange and flush mounted 4 inch lights require a 4-1/2 inch diameter hole.
    view full answer...
  • Troubleshooting Running Lights Circuit on a Travel Trailer Tail Light Harness
    Since you have tested the 4-Way connector on your vehicle and it is working properly, it leads me to believe that the wiring of the lights is incorrect. You will want to make sure that the fuse for the running lights on the vehicle is not blown. It sounds to me like the lights you have only have two wires coming out of the back for wiring to the trailer connectors wiring. If this is the case then the red wire will connect to the yellow (left) and green (right) wires on the trailer lights....
    view full answer...
  • Is there a Trailer Tail Light that Matches Peterson Back Up Light # 411SC
    We do not have an exact match for a red round tail light like the Peterson Back Up Light, # 411SC, that you have referenced that is a flange mount. The closest flange mounted lights are going to be the Peterson round tail lights # 431800 and # 432000. For a flush mounted light, you could use # 429800 which may be more what you are looking for. We also have the Optronics brand flange mounts # STL42RB or # ST47RB. They use wiring harness # A45PB.
    view full answer...

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Info for this part was:

Expert Research:
Michael H
Expert Research:
Jeff D
Expert Research:
John H
Updated by:
Laura H
Updated by:
Brian T

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