Expert Quality, 6 point deep socket forged from chrome vanadium steel hardened and tempered with a polished finish. Each socket has a knurled ring for extra grip. Fitted with rubber insert for spark plug insulator protection and retention. Features and Benefits • Expert Quality • 1 x 10mm thread (16mm socket), 1 x 12mm thread (18mm socket), 1 x 14mm thread (21mm socket) • Forged from chrome vanadium steel hardened, tempered, chrome plated and polished for corrosion protection. • Fitted with rubber insert for spark plug insulator protection and retention Contents 1 x Thread (16mm socket), 10mm 1 x Thread (18mm socket), 12mm 1 x Thread (21mm socket), 14mm