GEARWRENCH sockets are manufactured from alloy steel for maximum durability and strength. Our off corner loading design reduces fastener rounding and the chamfered opening help guide the socket on to fasteners. Our sockets feature a double line (SAE) and knurled (metric) ring help easily identify standard and metric sockets. The 13 piece 1/2"" Drive 6 Point Metric Standard Length Socket Set includes sizes: 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, & 24mm and includes a socket rail for socket storage and organization.