Descriptions:This screw extractor set is designed to remove broken studs and bolts. Made of premium Chrome vanadium steel material, and treated by heat treatment, with high hardness and wear proof. And contains 10 pcs different size extractors of 3.2-10.3mm, so can meet your repair work under different circumstances..Features:This screw extractor set is designed to remove broken studs and bolts.Made of premium Chrome vanadium steel material,and treated by heat treatment,with high hardness and wear proof.Reverse spiral design for maximum grip, so helps relieving your labor.Recommended drill bit size (for location hole) etched on each extractor,suitable for high torsion applications.This product contains 10 pcs different size extractors of 3.2-10.3mm, so can meet your repair work under different circumstances.Specifications:Material: chromium vanadium steelColor: grayQuantity: 10 pcsWeight: 537gSize: 1/8"(3.2mm), 5/32"(4mm), 3/16"(4.8mm), 7/32"(5.5mm),1/4"(6.3mm), 9/32"(7mm), 5/16"(8mm), 11/32"(8.7mm), 3/8"(9.5mm), 13/32"(10.3mm)Package Included:10 x Screw Extractor 1 x Red Case.