This Westward Hollow Shaft Nut Driver Set is a 7-piece set of hollow round shank nut drivers that comes in seven different sizes. This SAE tool kit is great for getting into tight spots and provides control when needed. Each solid round shank nut driver has a hex size of 3/16 in, 1/4 in, 5/16 in, 11/32 in, 3/8 in, 7/16 in and 1/2 in. It also features a screwdriver and nut driver grouping that helps keep your tools organized so that they are ready for your next project.