Hand socket wrenches are drop forged from steel bar. These wrenches are available in drive sizes of 1/4 in, 3/8 in, 1/2 in, 3/4 in and 1 in. These sockets are available in 6 point and 12 point openings in fractional sizes. Metric sizes available through 1/2 in drive. They are available in chrome and industrial black finish. These are special purpose wrenches designed for use in a wide range of sizes and capacities. All have square drives and drive size is a measure of capacity. As detachable socket wrenches provide an almost endless combination of handles, attachments and sockets, it is possible to assemble a proper tool for almost any type of service within the tools capacity. Martin Hand Socket, Standard Type II, Measurement System: Metric, Square Drive, 3/8 in Drive, 13 mm Socket, 25.7 mm Overall Length, 7.9 mm Opening Depth, 18.8 mm Drive End Width, 18.8 mm Socket End Width, Forged Alloy Steel, Polished Chrome