Features Broken Screw Extractor Easy to use, drill a hole in the center of broken screw first, then use a proper extractor to take screw out. You may use an adjustable wrench to hold extractor firmly when removing screw. This set is designed to remove damaged, rusted or stripped screws, bolts, fasteners. Tool steel extractors have left handed spiral flute designed for extra gripping power,high strength, high cost performance. There are total 5 extractors in various sizes for screws of diameter from 4mm to 18mm,Widely use Most people's choice, saving your work time. Specifications: Material: GCR15 tool steel Suitable Screws(Diameter): 1#: 4~6mm 2#: 6~8mm 3#: 8~11mm 4#: 11~14mm 5#: 14~18mm Package Includes: 5 x Extractors Package List