Simple You only need to turn the knob on the battery lightly, and the spare key can realize the disconnection and reconnection of the battery, which is easy to operate. Premium Materials: Kill Switch Key is made of ABS plastic and solid brass nut, which is strong, to use, not easy to and corrode, and has a long service life. Eliminates Power Drain: It can safely disconnect the battery, eliminating any power drain from the battery when the vehicle or boat is not in use, helping you save power. Wide Range of Applications: Kill Switch Key is suitable for a variety of applications, including automobiles, ships, ships, trucks, etc., with a wide range of uses Battery Disconnect Switch: Dimensions (LxW): Approx. 47 x 43 mm / 1.85 x 1.69 inches, fits a standard size battery disconnect switch, can be placed on the front, rear, left and right of the vehicle