This magical little box simulates the electrical load of an incandescent bulb, correcting some of the problems that can occur when all of the turn signal lights on a circuit have been converted from incandescent to LED. LED lights do not pull as much load, and sometimes they do not trigger the vehicle’s flasher properly. Wiring this load resistor into the circuit will add additional pull and cause the turn signals to function correctly. Sold SINGLE – you will likely need one per side.