The Longacre battery master switches are available in two formats. A 2 terminal switch which acts as a battery isolation switch that will ensure complete electrical isolation of the vehicle when it is switched off, so it cannot be re-started. A 4 terminal switch will ensure complete electrical shutdown on a running competition car when operated. It also prevents damage to the alternator diode and prevents engine run on when operated.Completely sealed and waterproofed with a tough waterproof polymer coatingBright red handle makes it easy to find in an emergency175 amp continuous rating, 6-36 volt with a 1000 peakThe switches feature a bright red handle that is easy to find in an emergency and will work with 6, 12 or 24 volt systems. The units are completely sealed to keep dirt and moisture out that could turn a critical switch into a useless dead connection and possibly ending your race.