Master Battery Disconnect Switch with Keys - This 2 stud Master Disconnect Switch is rated for 6 - 36 Volts and 180 Amps. It is designed for 12 VDC vehicles (truck, auto, marine, RV) to disconnect all circuitry, reducing the possibility of theft and accidental electrical fires. It does not disconnect the alternator or generator field circuit, and on vehicles equipped with alternators the engine must be shut off to avoid potential damage to alternator diodes. It has a one piece die-cast housing sealed with O-rings at the base and mounting stem to keep out dust and moisture. It has 2 - approx. 3/8 inch copper alloy stud terminals with hex nuts and lock washers. Measures approx. 4-3/8 inch Overall length, and 2-5/8 inch Diameter with a 3/4 inch diameter mounting stemand will fit panels up to about 1/4 inch thick.