DESCRIPTION Dual Battery Connect 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! LED Digital Double Voltmeter Round panel voltage monitors the 2 battery packs of the vehicle in real time, reminds you to charge or replace it in time, and better avoid battery exhaustion when starting the car engine! A must have for dual batteries Smart dual battery isolator help you run the radio, lights, and any other accessory without worry of the vehicle not starting. Waterproof and Dustproof feature Unlike other isolators on the market, Automatic 140 Amp Dual Battery Isolator is IP65 Certified. This International Protection rating means that your Kemimoto isolator is safe for use even for your off-road needs in dusty, wet and unexpected extreme weather environments. SKU: B0401-01301BK FITMENT Smart dual battery isolator compatible with most RVs, Cars Vehicles, ATVs, UTVs, Polaris, Can Am, Boats, 12VDC Marine, 4wd, caravan, etc.