The GEARWRENCH® locking extensions are a must for professional and industrial users. The locking mechanism holds the socket on the extension allowing the user to reach the most obscure locations without worry that the socket will fall off. The knurled grip provides non-slip surface. Extensions have a full polished chrome finish to resist rust and corrosion. GEARWRENCH® Adapter Set, 4-Piece, Measurement System: Imperial, Chrome Vanadium, Polished Chrome