Victron Energy Argofet Battery Isolator 100-3AC (3 Batteries 100 amp)A battery isolator that allows three batteries to be charged simultaneously from a single alternator without directly connecting the batteries together. This model automatically adjusts between 12-volt and 24-volt systems. Unlike diode isolators, FET technology provides minimal voltage loss of less than 0.02 volts at low current and averaging 0.1 volts at higher currents. This prevents the accessory battery from discharging the starter poundsProductdimensions7.9 x 4.7 x 2.6 inchesMaterialPlastic