Protects sensitive electronics by temporary isolation of house loads from engine circuit during engine cranking. Designed for 12 or 24 volt systems. 12/24 volt auto ranging voltage input. Hermetically sealed contacts/vaporproof. Waterproof rated IP67ùtemporary immersion for 30 minutes. Ignition protectedùsafe for installation aboard gasoline powered boats. Remote LED output indicates relay state away from ACR. Supports high-output alternators up to 120 Amperes. Dual sensing.