The Wiha Screw Extractor Set 16 Piece are for thread-conserving removal of damaged or broken-off screws with left-hand or right-hand thread, particularly stripped hex screws. Simply hammer in the extractor, position the ring spanner to the bottom and screw out without tilting. Supplied in a handy carry case. Contains the following: 8 x Screw Extractor Drill Bits: 2.3, 2.8, 3.4, 4.5, 5.7, 6.8, 9.0 &11.0mm. 8 x Screw Extractors: 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0 &10mm.