SPST On-Off Toggle Switch (1 Per Quantity) Typical applications: industrial controls marine panels trucks buses and automotive. Materials: brass terminals frame and support are steel with zinc chromate case is black phenolic plasic (flammability rating: UL 94 flame class 94V-1) and all other external parts are brass/bright nickel. Recommended mounting hole: 1/2" diameter. Single Pole Rated: 10A/277V AC; 20A/125V AC; 21A/14V DC; 3/4 HP 125-250V AC.