Made of chrome vanadium steel with long life and durability. Strong interior hexagonal sleeve without magnet. This set of screwdriver bits fits most corded or cordless powered drills to drive hex head screws. 9 hex sockets: 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm. Many uses. Suitable for household DIY, woodworking, auto parts, professional machine repair, etc.