Industrial design cam action mechanism insures quiet switch action. Color-coded faces identify amperage: blue-15 amp, red-20 amp, green-30 amp. Automatic grounding system eliminates need for bonding jumper in grounded metal enclosure. Backand side wire terminals accept up to number 10 solid or stranded wire. Ground screw terminal standard. 0.050" thick steel mounting strap zinc-plated for corrosion resistance. 30 amp, 120/277 volt rating for fluorescent lighting fixtures. Combination slot/Phillips head mounting and terminal screws. Meets all UL 20 requirements, Federal specifications WS 896.