WHOLESALE Useful for automotive, woodworking, small vehicle repair, farm equipment repair, electronic repair. Color coded for easy size identification standard 1/4 inch inch hex shank chucks securely into drills, quick-chucks, and bit extensions. Magnetic inserts hold nuts securely. Sizes: 1/4 inch5/16 inch3/8 inch7/16 inch1/2 inchIllinois Industrial Tools