REST ASSURED TO PURCHASE: We offer 30-day money-back for any reason, 12-month warranty for quality-related issues. Any problem in using our battery disconnect switch, please kindly contact us, your problem will be solved within 24 HOURS DURABLE&HIGH QUALITY: The battery cut off switch is made of zinc alloy with brass plating, corrosion resistance. Widely used for car, boat, truck, RV vehicles and electrical equipment EASY TO SWITCH ON AND OFF: Disconnect or connect battery by twisting the green knob a few turns. And also you can take the knob off to prevent vehicle theft. Much easier than taking the battery cable off each time EASY TO INSTALL: It only takes 5 steps to install. 1, Make sure the negative battery post and battery clamp (original battery connector) clean before installation. 2, Tighten the green knob. 3, Remove the negative cable from battery. 4, Install the disconnect switch on the battery post. 5, Install the cable on the stud end of the disconnect switch EXTEND THE LIFE OF YOUR BATTERY: The battery kill switch helps to disconnect battery easily to prevent it from draining down when not in use