DEWALT Impact Torsion Bits PH2 25mm Tic Tac Display 21 PieceThe DEWALT Impact Torsion Phillips Bits have a 15 torsion zone that allows the screw driver bit to flex rather than break, and the full fit head prevents rounding of the screw head and prevents 'cam out' (bit head slipping out of the screw head due to the turning force). The magnetic screw lock enables tasks to be completed quicker and easier, reducing instances of dropped or lost screws.