Complete Size Set - This 3-Piece Impact Universal Joint set includes 1/4, 3/8 and 1/2-inch Drive U-joints. Designed for use with all cordless, electric and pneumatic impact wrenches.Material - The impact swivel socket is made of premium chrome molybdenum steel with a corrosion-resistant black phosphate finish for durability. Precisely machined and heat treated for strength.Full 360 Motion - Each wobble socket has a full 360-degree rotation that lets you access hard-to-reach angles. Allows U joint swivel sockets to access complete rotation to reach tight spaces and access hard to reach fasteners.Durable Construction - Spring-loaded detent ball design will prevent dropping, and the through-hole in the drive end will locks socket into place for security. High-contrast size marking is permanently laser and easy to read, even in low light.Service Guarantee - All swivel sockets meet or exceed DIN standards. Please just let us know if you have any problem with the universal joint socket set. Coated with Manganese Phosphate treatment for maximum corrosion and rust protection.