VOLTAGE SENSITIVE RELAY: The Newdeli Automatic 140 Amp Dual Battery Isolator is all you need to charge Two Battery Systems. Voltage Sensitive Relay (VSR) cuts in at 13.3 volts and cuts out at 12.8 volts to ensure your primary battery is always charged and ready to start your vehicle. It's like having two separate power sources for each battery while only having one alternator!.Zero Voltage Drop: This Dual Battery Isolator is the only unit designed with cutting edge programming to deliver optimum performance.When the voltage of the start battery drops the isolator kit disengages from charging the auxillary battery.This isolates the start battery and eliminates the possibility of draining it, ensuring that you always have enough charge to start your engine..RUGGED DURABILITY: Unlike other isolators on the market, the Newdeli Automatic 140 Amp Dual Battery Isolator is IP65 Certified. This International Protection rating means that your Newdeli isolator is safe for use even for your off-road needs in dusty, wet and unexpected extreme weather environments. Great for extreme vibration applications as well..WHAT YOU GET: 12V 140Amp Smart Battery Isolator；1 x 6 metre length of 8AWG red cable terminated at both ends;1 x 60cm length of 8AWG black earth cable terminated at both ends;2 x Positive Marine battery terminals;1 x Negative Marine battery terminals;3 x SC16-8 Copper crimp lugs;2 x Red heat shrink ;1 x Black heat shrink; 1 x Insulated blue ring terminal; 6 x 300mm cable ties; 4 x Self tapping screw; 3 x M6 nut; 4 x M6 spring washer.COMPATIBILITY:This battery isolators designed for:ATVS, UTVS, Boats, RVS，CAT, campers, 5th wheels, offroad vehicles, rhino, polaris, artic, marine vehicle, truck, caravan, ETC.