The main difference between the Fusion LED Trailer Tail Light part # STL211XRFHB and the Fusion LED Trailer Tail Light part # OPT37FR is that the stop/turn signal portion of the former is a red lens with red LEDs and the latter is a white lens with red LEDs. The white lens with red LEDs will be brighter/clearer hence the price increase. I recommend the latter as our best option for clarity. view full answer...