Easy to UseKnob type design to disconnect or connect battery, just follow the direction instructions on the switch, unscrewing or tightening the battery switch into an on or off position to control current. Compatible- The battery disconnect switch is used for top post terminal(0.59''- 0.67'' cone battery negative post only). Compatible the condition of 12V voltage, 125A rated current, heavy duty. High Quality- Our solid brass 12v battery disconnect switch with stainless steel fasteners provide excellent oxidation resistance and corrosion resistance, no need to worry about its service life. Widely Applications- Suitable for Car, Marine,tractor, camper, boat, RV, truck batteries which have a standard 0.59''-0.67''(15-17 mm) cone top post terminal, also used for electrical equipment. Protect BatteryThis battery shut off switch is designed to cut-off power flowing to the battery, avoid unwanted battery consumption when not used for long periods of time, extend the life of battery.