Equip your semi to be Ready for the Road Ahead , with the Grote 9/16V Automatic Electronic Dome Light Switch, a reliable component that controls the lights in the cab. With a pre-set timer, this replacement device works to automatically shut off the internal lights whenever forward or backward motion is detected. Crafted with polycarbonate and nylon materials for long-term reliability and heat resistance. FleetPride is your First Click in Heavy Duty .