Features Easy to use, drill a hole in the center of broken screw first, then use a proper extractor to take screw out Tool steel extractors have left handed spiral flute designed for extra gripping power This set is designed to remove damaged, rusted or stripped screws, bolts, fasteners There are total 5 extractors in various sizes for screws of diameter from 4mm to 18mm You may use an adjustable wrench to hold extractor firmly when removing screw Features: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.There are total 5 extractors in various sizes for screws of diameter from 4mm to 18mm. 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. Specifications:Material: GCR15 tool steelSuitable Screws(Diameter):1#: 4~6mm2#: 6~8mm3#: 8~11mm4#: 11~14mm5#: 14~18mm Package Includes:5 x Extractors Package List