4" Round Red 10 LED Trailer Truck Brake Stop Turn Tail Lights / Grommets1 Pair of 10 LED Red Stop Turn and Tail lights Light is 4" in diameter. Requires a cutout hole of approximately 4. 5" 12V DC power DOT approved. Direct wired with 3 wire pigtails for ground, brake turn and tail light These Lights are impact resistant and less susceptible to shock damage. Each LED Light is water tight sealed. These LEDs draw less current, generate less heat and are brighter and light faster than an incandescent bulb