Universal dual filament lamp holder BA15D

Compatible with any regular dual filament (dual circuit) light bulb with 1157 style fitting Allows you to convert your single circuit turn signals to dual circuit for running lights, building your own custom taillight/brake light etc. Takes any regular dual filament bulb with #1157 style fitting (base pin placement at 3 and 9 o'clock). Complete with attached mount bracket. Outside diameter 16.7mm, total length 31.5mm.