Perko Dual Battery Switch w/Mounting Ring & Legs - Bulkhead Mount. This switch provides the flexibility of selection between batteries or combined operation of both batteries in parallel for starting or charging. It can also serve as an emergency main disconnect switch in the event of an electrical problem. All models are make before break design and are ignition protected.Four switch positions: Both "Off" Both "On" Battery 1 "On"/Battery 2 "Off" Battery 1 "Off"/Battery 2 "On"Materials & FinishRed polycarbonate polymer body Black polymer actuator key Nickel plated terminals Specifications for Perko Dual Battery Switch w/Mounting Ring & Legs: Manufacturer: Perko Color: Black Features of Perko Dual Battery Switch w/Mounting Ring & Legs Rating: 140 Amps Continuous 200 Amps 5 Min. Intermittent 250 Amps 30 Second Start Installation Hole Size: 3" For use with alternators and generators 6-50 V.D.C. Marine Electrical Systems Ignition Protected Face Dimensions: 3-7/8" x 3-1/4" Package Contents: Perko Dual Battery Switch w/Mounting Ring & Legs Perko 8521DP: Dual Battery Switch w/Mounting Ring & Legs - Bulkhead Mount