Suitable for different types of batteries with terminal diameters of 15-17mm. To turn on the power, just tighten the green thumbwheel slightly. Loosen it slightly to cut off the power. Battery and system master circuit breaker, save your car power, protect the whole system from draining out. For 6V, 12V and 24V battery systems, 500 Amp surge rating and 125 Amp continuous rating. Easy to use power cut off switch disconnect, allowing you to quickly disconnect your battery for safety, car maintenance or storage. Universal for cars, boats, trucks, RVs and more.