Perko Medium Battery Selector Switch w Key Lock The Perko 8502 Battery Switches are among the most popular battery switches in the marine industry. Designed for surface mounting, the Perko Battery Selector Switch has a bright red polycarbonate housing with a large easy-to-turn black knob. High conductivity studs are long enough to handle more than 1 cable and strong enough for torque needed for secure connections. This switch can be mounted in numerous locations, and since it is ignition protect