This 14-piece power nut driver bit set features sandblasted, chrome vanadium steel, precision-milled, 1/4"-hex shanks made to fit all power drills, screwguns, and cordless and magnetic screwdrivers. It contains seven power nut driver bits (SAE): 3/16-inch, 1/4-inch, 9/32-inch, 5/16-inch, 11/32-inch, 3/8-inch, and 7/16-inch, and seven other power nut driver bits (metric): 5 mm, 5.5 mm, 6 mm, 7 mm, 8 mm, 10 mm, and 12 mm. It also comes with a plastic storage clip designed to fit on workbelts.