The Automatic 140 Amp Dual Battery Isolator is all you need to charge Two Battery Systems. Voltage Sensitive Relay 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! Unlike other isolators on the market, the Automatic 140 Amp Dual Battery Isolator is IP67 Certified. This International Protection rating means that your 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. This battery isolator suitable for 12V 140 Amp, Truck, SUV, RV, ATV, UTV, Boat and so on. Forget the traditional diode relays and so-called "solid state" devices that can rob you of almost 2 amps of output power! The Dual Battery Isolator is the unit designed with cutting edge programming to deliver performance - with ZERO sacrifice. This compact battery isolator was built ultra-small to fit almost anywhere! A perfect fit under the hood to get close to your dual batteries. Cause your accessories to run from a separate battery while the engine is not working on your vehicle, and at the mean time holding your main battery charged and your vehicle always ready to work. Continuous Rating: DC 125A Intermittent Rating: DC 140A Power Consumption: 10mA (Standby)/ 330mA(Engage) / 0mA (Storage) Terminal Studs: M6(1/4inch) colour: black Material: ABS Size: 6.5cm x 6.5cm x 5cm Package Contents: 2 x 140 AMP Battery Isolator 2 x Blue Ring Terminal 8 x Screw 2 x English manual