7-Pin tumbler mechanism. Key is removable ONLY in the OFF position. When Key is turned to ON Position and released it will return to OFF Position. Includes key switch, 2 keys and nut. Keyed differently - each purchased lock has a different key number. Terminals: tubular solder cups. Zinc alloy die cast and cylinder. Steel tubular keys, nickel plated. Spring loaded for momentary contact. Silver plated contacts and terminals. Barrel length: 1.25". Barrel diameter: 5/8". Contact rating: 4A 125V AC; 2A 250VAC. Thread length: 7/8". Overall length including terminals: 1-3/4".