49pcs Screw & Bolt extractor Tool kit -- 13pcs Bolt extractor socket：1/4", 5/16" ,3/8", 10MM, 11MM, 12MM, 1/2", 13MM, 14MM, 16MM, 17MM, 11/16", 19MM ;13pcs Multi-spline Screw extractor :1/8", 5/32", 3/16", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 13/32", 7/16", 15/32", 1/2" ;16pcs golden drill bit: 5/64", 7/64", 1/8",5/32",6/16",7/32", 1/4", 9/32", 19/64", 5/16", 11/32", 3/8", 13/32", 7/16", 15/32", 1/2";6pcs spiral screw extractor:1#, 2#, 3#, 4#, 5#, 6# ; 3/8"Dr extension Bar. Multi-Application --Remove the broken screw first Select a suitable size golden drill bit to drill the hole and then select a spiral screw extractor to remove the screw. Drill bits could be used to bore holes on wood, metal, plastic and wall etc. Convenient to use --It provides maximum torque while reaching deeper screw removal locations. Capable of spinning out partly-exposed, damaged fasteners. Perfect for use in small areas providing the most torque while engaging without a deep hole. 41Cr4 Steel -- Each bolt extractor is made of high hardness 41Cr Chrome steel for ultra durability and tough strength to avoid damage during high-intensity use. Application -- Suitable for removing most damaged, frozen, rusted fasteners including bolts,nuts and screws. Bolt Extractor Set