Knob Battery Switch With Bypass For Side Terminal Battery. Very easy to install on negative battery post with its compact side mount battery switch with fused bypass. Battery is disconnected by unscrewing the knob a few turns, and reconnected by tightening the knob. Knob can be removed completely to deter theft. Compact size fits most battery compartments. Rated 500 amps surge and 125 amps continuous at 12 volts. 15-amp fused bypass maintains computer settings, radio, clock, etc., while battery is disconnected. California Prop 65 - Warning, This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm.