Sockets are heat-treated- alloy steel. Two tools in one; saves space in your pouch. One end opens telephone box fasteners- the other end tightens nuts on binding-post terminals. Sockets are 1-1/4in (32 mm) deep to fit over long binding posts and are thin-walled for easy access into tight areas. Socket ends are color-coded for quick identification of socket sizes. High-impact- break-resistant handle for long and dependable service. The 7/16in socket has a black finish and the 3/8in socket has a silver finish. Hex-socket design enables using a wrench to obtain extra torque.