No More Battery Drain Battery Isolator Switch helps isolate and secure the electrical system, eliminating power drain from the battery when the vehicle or boat is not in use. It safely disconnects the battery and improves battery lifespan. Good conductivity: The power switch is made of alloy with excellent plasticity and good conductivity, reducing voltage distortion and current transmission loss. Easy to use: The design of the power-off switch conforms to ergonomics. The side knob rotates smoothly, allowing easy and quick disconnection and reconnection of the power supply. Turn the knob until the thread is visible to disconnect battery power. Wide application: This battery shutoff switch is ideal for cars, boats, trucks, RVs, motor homes, jet skis, motorcycles, race cars, and other vehicles with top post batteries. Delivery quantity: 1 piece Package contents: 1 x Battery Isolator Switch Size: Aperture: 15.5-17mm; suitable for battery terminal: 15.5-17mm (Reminder: Size is measured manually; please allow 1-2 cm measurement error) Color: Black (Note: Due to different monitors and lighting effects, the actual color may vary slightly from the image.)