Witte screwdriver bits are made to very exacting standards to ensure maximum transmission of torque to the screw by a special hardening process and an exact fit of the bit to Pozidriv screws. In addition there is a special recessed neck called the Flex-Zone which absorbs shock loads thus giving increased durability. There is also a special coating of titanium nitride which increases the wear resistance of the Bitflex Pozidriv.The bits are packed 2 to a card, have 1/4in hexagon drive and are 25 mm long.