Medium Duty Battery Selector Switch – 250A Continuous. Features: For use with 6 two 50 Volt Marine Electrical Systems, Capacity – 250 AMPS Continuous, 360 AMPS Intermittent, When used with Non-Unitized Alternators, these models will interrupt the field current (reducing the possibility of damage) if turned “OFF” with the engine running , Specs: Diameter: 5-1/4″, Depth: 2-5/8″.