The Mayhew Tools 37331 Screw Extractor Set, 4-Piece, includes: 36966 Screw Extractor D15/32-Inch S3/4-Inch, 36967 Screw Extractor D9/16-Inch D7/8-Inch, 36968 Screw Extractor 21/32-Inch S1-1/8-Inch, and 36969 Screw Extractor D13/16-Inch S1-3/8-Inch. Screw extractors are used for removing broken or seized screws. Its hardened steel edges allow for easy screw removal. The fluted cutting edges cut into the screw shaft to remove the screw. Made in the USA. Mayhew Tools specialty tools are designed for tough applications. Engineered to tackle specific and sometimes trying applications, our specialty tools are developed to tackle the jobs that no other tools do. These tools are designed to make tasks simpler and safer, saving you both time and frustration. Unlike anything else on the market, our specialty tools work hard—even in confined spaces—so you don’t have to.