Made of chrome-vanadium steel with long life and durability in use. Solid inner hex socket without magnet. This screwdriver bit set fits most corded or cordless drills for hex head screws. 9 hex sockets: 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm. Many applications. Suitable for household DIY, woodworking, auto parts, professional machinery repair, etc. This is a set of 4 durable reducer and increaser adapters. Heavy-duty chrome-vanadium steel construction is designed for use with ratchets. A black oxide finish makes each piece corrosion resistant and highly durable. The spring-loaded ball stop keeps your sockets stationary and secure. There is a range of sizes to fit many socket or wrench combinations, including 1/2"(M)–3/8"(F), 3/8"(M)–1 /4"(F), 3/8"(M)–1/2"(F) and 1/4"(M)–3/8"(F). Specifications: - Material: Chrome Vanadium Steel -Surface finish: electroplating, blackening - Hardness: 45 ± 2 (HRC) -Color: black -Size: 1/2"(male) - 3/8"(female) 3/8"(male) - 1/4"(female)