Buyers Products 4 Inch Round Stop/Turn/Tail Light with 7 LEDs is commonly used on trucks and trailers to meet FMVSS/CMVSS 108 regulations.
The light has a red lens and uses a PL-3 connection. 4 in. black grommets are also available for mounting.
Lights are available in bulk (sold in multiples of 10) or as individual kits that include a grommet and plug. They are backed with a limited lifetime warranty.