Maximum load 1000 amps at 12 volts (Peak) . Excellent boat safety/anti-theft device. May be fitted to either the positive or the negative circuit. The key can be removed when in the 'off' position. Seawater proof. Housing and key are made from durable plastic. Maximum loading: 12 volt 1000 amps for 10 seconds 24 volt 500 amps for 10 seconds