Tapered designed for removing damaged screws. Suitable for both clockwise and anti-clockwise threads. Square shank and manufactured in CR-V 6150 steel hardened to HRC50-52. Use with drill sizes 3, 4, 5, 7 and 9mm. Use with the Teng Tools tap handle (TAP-HNDL). Supplied in the Teng Tools TJ case with clear lid and belt clip.