Teng M120611C Bi-Hexagon Socket Deep 12 Point 1/2in Drive 11mm. Size: 11mm. A professional bi-hexagon 1/2in Square Drive deep socket produced in accordance with ISO 900 and AS954 specifications for increased torque and reduced risk of rounding fasteners. Manufactured from chrome vanadium steel with a satin finish. Length: 79mm.Size: 11mm.