Material: High carbon steel, material to prevent damage during use. General use: Designed for use with impacts, these extensions, adapters and reducers feature spring-loaded detent balls to safely engage Lifting Comfort no matter what tool you're using. Ideal for DIY, household and most general repairs, not for industrial work. A great addition to any tool box set. : Extension adapters are made from heat treated chrome vanadium steel with a black oxide coating, and adapters and reducers are made from premium high strength chrome moly. steel with a manganese finish - Phosphate coating to ensure rust and corrosion resistance for a lifetime of use. Widely used: suitable for 1 or 4" quick change chuck systems 4 inch or directly into the drill chucks. Any cordless drill that examines an electric screwdriver. Convenient for quickly driving in nuts, bolts and fasteners etc. Spring-loaded ball bearing on head holds sockets securely. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.