7610120 Amp SI-Series Automatic Charging Relay Allows temporary isolation of house loads from engine circuit during engine cranking to protect sensitive electronics Automatically combines battery banks during the charging cycle and isolates under discharge 12/24 Volt auto ranging voltage input Waterproof rated IP67 temporary immersion for 30 minutes Ignition protected safe for installation aboard gasoline powered boats Remote LED output indicates relay state away from ACR LED light indicates when batteries are combined LED blinks in undervoltage lockout and starting lockout Supports high-output alternators up to 120 Amperes Included with the ADD A BATTERY Dual Circuit System Automatically combines battery banks during the charging cycle and isolates under discharge Ignition protected safe for installation aboard gasoline-powered boats Activates from any charging source alternators, battery chargers, or solar panels Hermetically sealed contacts / vaporproof Side and bottom knockouts for power cable connections Clip-on cover protects and insulates terminal connections Tin-plated copper studs for maximum corrosion resistance 7/8 22.22mm stud length to accept multiple cable terminals 1/4 x 0.031 male quick connect terminals for ground and remote LED and starting interrupt 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.