1. Upgraded Design: Our screw extractor set features a doublehead design that connects directly with your wrench no connecting sleeve needed! This innovative approach allows you to tackle damaged bolts with greater efficiency and less frustration, saving valuable time on your projects. 2. Grip Technology: Engineered with a spiral lefthand structure, these hex head multispline bolt extractors provide exceptional gripping power on stripped fasteners. The density spiral design creates faster threading speeds and reliable performance even on the most challenging damaged screws and rusted bolts. 3. ProfessionalGrade Materials: Crafted from heattreated chromium steel, these extractors deliver impressive strength and longevity. The construction offers grip strength to handle stubborn fasteners while maintaining integrity through repeated use on tough extraction jobs. 4. Comprehensive Size Range: This versatile 15piece set includes extractors in sizes from 18 to 12, with clear size engravings on each socket for quick identification. Fits various bolt head sizes (8/10/11/12/13/14mm(3/8''), 16/17/19mm) to address virtually any stripped or damaged fastener problem you encounter.