Battery Master Switch 300A Heavy-duty battery master switch designed for demanding automotive environments in motorsport. Rated up to 300A and suitable for 12-48V DC systems, making it ideal for race cars, track day vehicles, and other high-performance applications. The switch mounts directly to the negative battery terminal (top-post 15-17 mm) and provides fast, safe, and efficient power isolation. Equipped with solid copper terminals for low resistance and maximum current transfer. The clearly marked ON/OFF rotary knob with color indication allows quick power shut-off to protect the electrical system during service, transport, or storage. An additional M8 terminal allows connection of extra cables or accessories. Specifications: Function: ON / OFF Operating voltage: 12-48V DC Rated current: 300A Connections: 2-pole + M8 stud Terminal material: Copper Housing: ABS plastic Rotation angle: 90°