This 7 Piece Square Type Screw Extractor Set is manufactured from high-grade, heat-treated alloy steel for durability and resistance to corrosion. The chemically blackened finish further enhances its longevity. The square section design of the extractors aids in their removal from screws. This set is supplied in a convenient storage tray and comes with a lifetime guarantee. It includes extractors of sizes #1 (1/8"/3mm) through #7 (9/16"/14mm) and has a net weight of 0.30kg. B&Q offers a wide variety of tools and workshop equipment for both DIY enthusiasts and professionals.