Features: Manufactured from Chrome Molybdenum steel for strength and durability Spiral cut teeth provide a positive grip allowing extraction of damaged or rounded of hex bolts Can also be used on screw heads and studs Removal without damaging the casing or thread Reverse left-handed threaded sockets For use with a 3/8" drive ratchet, socket or spanner   Specification: Fits heads sized 9, 10, 11, 12, 13, 14, 15, 16, 17 and 19mm 1 X 7mm X 90mm Bar