The Do it Best 40-Piece Impact Screwdriver Bit Set is built for heavy-duty use, offering 50x life compared to standard bits. Designed to be torque resistant and impact-ready, this set ensures durability and reliable performance for your toughest jobs. Includes (21) 1" magnetic driver bits: (2) PH1, (4) PH2, (2) PH3, SL 3/16", SL 1/4", SQ1, (4) SQ2, SQ3, T15, (2) T20, (2) T25; (14) 2" magnetic driver bits: PH1, (2) PH2, PH3, T25, T30, T40, (2) SQ1, (4) SQ2, SQ3; (2) Impact Nut Setters: 1/4" and 5/16", (2) Impact Socket Adapters: 1/4" drive and 3/8" drive; and (1) 3" magnetic bit holder.