Ratchet Adapter Set Includes ---4 piece socket 1/4 to 3/8 - 3/8 to 1/4 inch - 3/8 to 1/2 - 1/2 to 3/8 High Quality---Extension adapters are made of chrome steel.Adapters and reducers are made of premium high-strength chrome steel with a manganese phosphate coating to help resist rust and corrosion. the corrosion and ensure a lifetime of use. Purpose General Use --- This Hex Shank Screwdriver Extension Bar Set is designed to meet a variety of needs. Provides versatility and convenience no matter which tool you choose to use. Purpose ---Spring-loaded ball lock ensures a tight fit in the drivers head to prevent slipping in use. Specially machined to fit securely in a hand screwdriver, drill key or impact wrench. ball bearing ch. Ideal helper for life and work Durable material Each part is made from chrome vanadium steel heat treated with a chrome finish for added durability and corrosion resistance to give them an extended life free of rust and corrosion from wear and tear normal. drills and drivers as well as ratchet and hand wrenches. Multi-size matching The set contains a variety of sizes, you can choose freely to match wide application in auto repairs, household maintenance and most general repairs.