This 6-Piece Set Features Extractors Made From Gcr15 Tool Steel Designed To Remove Damaged Rusted Or Stripped Screws Studs Bolts And Staples. Each Extractor Has A Left-Hand Spiral Flute For Enhanced Gripping Power. Suitable For Screws Ranging From 4Mm To 22Mm In Diameter. To Use Drill A Hole In The Center Of The Broken Screw Then Insert A Suitable Extractor And Use An Wrench To Firmly Grip And Remove The Screw.