5 pcs Screw Extractor Set.High quality group of pillar extraction apparatus through our professional Anti clockwise twist design. Broken bolt or screw drill, then extractor insert.Material:hard alloy steelSizes:1/8"-1/4", 1/4"-5/16", 5/16"-7/16", 7/16"-9/16" and 9/16"-3/4" (M3-M6, M6-M8, M8-M11, M11-M14, M14-M18)Features:Easy to useRemoves broken screws, bolts, and studs without damaging bolt or hole threads.Extractors have round flutesTempered chrome molybdenum steel.Includes a Plastic Storage CasePackage Included:1 X 5 pcs Screw Extractor Set