Staplers & Rivet Guns. Ratchet (72 Teeth). Sockets: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 27, 30 & 32mm. The set is heat-treated, hardened, tempered and fully polished. 21mm spark plug socket.