This Blue Sea Systems m-series battery switch has 300 amp continuous rating for outboards and small gasoline or diesel engines. Switches a single battery to a single load group. Tin-plated copper studs for maximum conductivity and corrosion resistance and accept 3/8" (M10) ring terminals. One-piece terminal stud design never loosens over time. Isolating cover with three snap-off side pieces protects rear contacts and allows wire access in any direction. Case design allows surface, front panel, or rear panel mounting. Ignition protectedsafe for installation aboard gasoline powered boats. Meets all American Boat and Yacht Council (ABYC) requirements for battery switches.