Professional Quality, sockets manufactured from chrome vanadium steel hardened, tempered and chrome plated for corrosion protection. Chamfered end allows positive nut location and entry. Hole for driving accessory spring-loaded ball. Sold loose. Manufactured and tested generally in accordance with DIN3122 and ISO3315 Specifications. Type: Bi-hexagon socket. Material: Chrome Vanadium Steel. Size: 7/16in. Drive: 1/2"" Sq. Dr.