High quality Alloy steel (S2) material. * Rapid, portable, remove the screw, pipe, bolts have been damaged. * Perfect for removing screw from wood. * Handle:Hexagon handle 1/4''(6.35mm). * Size of 4 models: #1. 3-5mm, #2. 4-8mm, #3. 5-10mm and #4. 6-12mm. * . * Reverse screw extractor and into the damaged screw counterclockwise, until removed. * Package includes: 4 x Double Side Damaged Screw Extractor S2 Alloy Steel Out Remover Bolt Stud Tool. * Usage: 1, With the speed can be change and -direction of the electric drill. 2, the first thing to determine when using extractor and ensure the safety of the tool and will not be moving. 3, the screw head be damaged thicker than extractor, with the drilling head end drill a hole( deep enough) in the middle of the screw head. 4, reverse screw extractor and into the damaged screw counterclockwise, until removed.