Single Circuit On/Off. CE Marked. Enables a failed House or Start battery bank to be isolated from the electrical system and both House and Start loads to be operated from the remaining battery bank. Simplifies battery switch operation. Isolates Start circuit from House circuit. Protects electronics from sags and spikes caused by engine cranking. Ignition protected - Safe for installation aboard gasoline-powered boats. WARNING: This product can expose you to chemicals including di(2-ethylhexyl)phthalate (dehp) which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.