The Do it Best 10-Piece Nut Driver Bit Set features extra-strength magnets for strong bit retention during tough tasks. With a 1/4" quick change shank and impact-ready design, this set is perfect for use with impact drivers and drills. It includes sizes 1/4", 5/16", 3/8", 7/16", and 1/2" in both 1-7/8" and 2-9/16" lengths.