MaterialHigh carbon steel, high quality material to avoid during use. General UseThese extensions, adapters, and reducers are designed for impact use and feature spring-loaded detent balls to lock sockets securely, while the through holes on the drive end of the adapters and reducers lock onto the drive shank. convenience, regardless of the tool you have chosen to use. Ideal for DIY, household maintenance, and most general repairs. High QualityThe extension adapters are made of heat-treated chrome vanadium steel with a black oxide coating. The adapters and reducers are made of premium, high-strength chrome steel with a manganese phosphate coating to help resist rust and corrosion. a lifetime of use. Widely ApplicationSuitable for 1/4" quick-change chuck systems or directly into the drill chuck. Any cordless power drill into a nut driver. Convenient for quickly driving nuts, bolts, and fasteners, etc. The spring-loaded ball bearing on the head holds the sockets securely. Number of Pieces Delivered: 7luckymeet