High amperage capacity: 300A at 12V DC. Protects vehicles against tampering, theft and battery drain. Protects from hazards during vehicle servicing, and can be locked-out or tagged-out. Provides an effective emergency power cutoff. Can be used in both positive or in negative path applications. Waterproof and dustproof to ip67 (immersible). Switch can be located in the best location, regardless of environment. Composite engineered polymer housing will not rust or corrode. Tested per SAE 1455 for salt corrosion. Large red knob is easy to operate with gloved hands; 90 switch travel makes it easy to identify the switch position. Built-in lockout satisfies osha requirements for an energy isolation device. Attractive styling suitable for visible mounting close to operator. Large divider on base prevents accidental shorting of high energy cables. Fits standard Master Disconnect mounting pattern. Knob is secured in place with a set screw.