Magneto Safety Kill Switch Marine emergency cut-off Kill Switch attaches to your life vest while operating a boat or personal watercraft. Designed to instantly cut battery power when detached. The magneto (red cap) version functions in applications where the circuit is normally open (not complete) with lanyard clip in place on switch. When lanyard is pulled and clip is removed from switch, circuit is closed (complete), allowing grounding to a suitable ground such as a grounding block, the battery, or a suitable area on the engine itself. The kill switch includes a coiled lanyard that is approximately 15" when coiled and 48" when stretched, which should be replaced if worn, cut, or frayed. Mounting hole is 5/8" in diameter. Maximum panel thickness: 5/8". Maximum 5A draw. WARNING: Switch should be tested for proper function before each use. WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.