Manufactured from Chrome Molybdenum hardened steel.Easily extract nuts, bolts and screws that are rusted, worn, painted over, or even completely stripped or broken.Internal thread with reverse spiral flutes for superior grip on damaged bolts, providing excellent torque. Includes standard 1/4" and 3/8"Sq drive hex adaptors, allowing the use of hand, air, or power tools. Includes three knock-out pins for easy removal of damaged bolts and nuts once removed.Contents: 25pc Multi Spline Hexagonal Screw Extractor Set - 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", 17/32", 9/16", 19/32", 5/8", 21/32", 11/16", 23/32", 3/4", 25/32", 13/16", 27/32", 7/8", 16pc Reverse Spiral Hexagonal Nut/Bolt Extractor Set - 3/8"Sq Drive/Hexagonal Drive; 1/4", 8mm 5/16", 3/8", 10mm, 11mm 7/16", 12mm, 1/2", 13mm, 14mm 9/16", 16mm 5/8", 11/16", 1/2"Sq Drive; 17, 19, 21, 22, 24mm, 5pc Spiral Flute Screw Extractor Set - 4, 5, 6.5, 8, 11mm, 5pc HSS Drill Bit Set - 2, 3, 4, 6, 7mm, Hex 3/8"Sq Drive Adaptor, Hex 1/2"Sq Drive Adaptor, 3pc Reversible Knock-Out Pin Set - 5-10, 7-12, 10-10mm.Supplied in durable storage case for easy transportation. Model No. AK8156CHROME MOLYBDENUM STEEL – Hardened and tempered steel for strength and durability. KNOCK OUT PINS – For easy removal of damaged bolts and nuts once removed. EASILY REMOVE BROKEN NUTS – Easily extract nuts, bolts and screws that are rusted, worn, painted over or even completely stripped or broken. REVERSE SPIRAL FLUTES – Internal thread with reverse spiral flutes allows for secure grip on damaged bolts, providing excellent torque. COMPRHENSIVE KIT – Includes 1/4” and 3/8”Sq Drive hex adaptors, allowing the use of both hand or air power tools. SUPPLIED IN STORAGE CASE – For easy transportation and storage.