The DEWALT Impact Torsion TORX Bits have a 15° torsion zone that allows the screw driver bit to flex rather than break and a full fit head prevents the rounding of the screw head and prevents 'cam out' (bit head slipping out of screw head due to the turning force). The magnetic screwlock enables tasks to be completed quicker and easier, reducing instances of dropped or lost screws. Supplied in a pack of 5. Ref: UTTK7178