The BlueSpot Nut Driver Set is manufactured from heat-treated, chrome vanadium steel for increased durability and has a sandblasted finish to protect against corrosion. With 1/4in drive, ideal for use with power drills and electric screwdrivers. Supplied in a robust belt clip for convenient access and storage. Sizes are clearly marked on the clip for easy identification. This 14 piece set contains: 7 x 1/4in Imperial Nut Driver Bits: 3/16, 1/4, 9/32, 5/16, 11/32, 3/8 and 7/16in 7 x 1/4in Metric Nut Driver Bits: 5, 5.5, 6, 7, 8, 10 and 12mm