Provides 4-way selection for battery 1 / 2 / both, and off. The switch itself is very durable and rated for massive output. It features removable windows on all four sides to cater for whatever cabling arrangement you have. Alternator Field Disconnect (AFD) protects your alternator when switching batteries in and out of the circuit. By disconnecting the alternator moments before the battery (moments after when re-engaging), there's always a load on the alternator to protect the regulation circuitry. Specifications: Mains Voltage Range : 48V Packaged Volume : 1.44l Packaged Weight : 0.3kg Packaged Length : 16.9cm Packaged Width : 10.3cm Packaged Height : 8.3cm High Current Rated Protects your alternator Versatile cable entry Continuous Current: 200A Surge Current (5min): 300A Cranking Current (10 sec): 1000A