High-Quality: Forged from chrome vanadium steel, it is stronger than tool steel, bolt extractors have oxide surface provides greater strength and durability and prevents corrosion. Professional Tools:Bolt nut removerReverse spiral flutes are designed to bite down to provide Maximum gripping power. Metric and SAE:The set includes Metric and SAE sizes - 1/4", 5/16"(8mm), 3/8", 10mm, 7/16"(11mm), 12mm, 1/2", 13mm, 9/16"(14mm), 5/8"(16mm), 17mm, 11/16", 3/4"(19mm) Universal Design:3/8-Inch square drive for use with hand ratchets, impact wrenches and air ratchetsExtractor sets have hexagonal flats for use with flat wrench, pliers, adjustable wrench, sockets or Vise-Grip locking pliers Warranty Service:If you have any problems with our products.