Screw Extractor SetPack of 6Removal of damaged screws, bolts and studs.Manufactured from hardened carbon steel.Product features a reverse thread.Insert into pre-drilled hole within screw.Operate drill slowly in reverse to bite and remove screw.The squared end also allows use with a tap wrench.Complete with storage case.Sizes3 - 6mm.6 - 8mm.8 - 11mm.11 - 14mm.14 - 18mm.18 - 25mm.