12V DC. Hundreds of uses. For 'door ajar' warning, bus driver alert, low air pressure, temperature, etc. Works with any temperature, pressure, door or momentary switch. Electrical contacts are designed for instant response and uninterrupted signal. Impact-resistant ABS resin case. Moisture-repellent insulator. Two screw terminals with lock washers. Size: 1 7/32-Inch Long x 2 1/2-Inch Wide x 2 17/32-Inch High (30.9 x 63.2 x 64.3mm). Replaces: Ford FDM-2938-A, GMC 1116882, Superior Coach 76032, Divco-Wayne E-11811-A.