This is a waterproof DC Circuit breaker. Surface mount means that it screws to a bulkhead and the wire connections are at the front. It has a bright yellow lever making it easily visible and the circuit breaker can do double duty as a switch. It is ignition protected so it can be used on board gasoline boats
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.