Features High Hardness And Durability: Set of 10 screw extractors are made of selected chrome vanadium steel and forged by heat treatment, it has high hardness and durability. Remove Damaged Bolts And Screws: This screw extractor kit is designed to remove damaged bolts and screws, it is a very practical tool, with a storage box, very convenient for us to use. Reverse Spiral Design: The broken wire extractor is designed with a reverse spiral for maximum grip, so it can help reduce your manual effort. 10 Different Sizes: The screw extractor kit contains 10 different size extractors from 3.2-10.3mm, so it can meet your repair work in different situations. Strict Workmanship: The screw extractor set has undergone strict workmanship, the surface is polished flat, and the drill bit size (for location holes) etched on each extractor is recommended for high torque applications. Features: 1.This screw extractor set is designed to remove broken studs and bolts. 2.Made of Chrome vanadium steel material,and treated by heat treatment,with high hardness and wear resistance. 3.Reverse spiral design for maximum grip, so helps relieving your labor. 4.Recommended drill bit size (for location hole) etched on each extractor,suitable for high torque applications. 5.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 steel Color: gray Quantity: 10 pcs Weight: 537g Size: 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 Package List