6-point hex socket for maximum torque transfer to the face of the fastener. Precision cold forged, hardened and tempered chrome vanadium steel. Fully polished and nickel chrome plated for durable corrosion resistance. Chamfered ends and thin walls for positive location on fastener. Knurled band for grip. Contents: 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 11, 12, 13 and 14mm.