Product description: Quantity: one set (7 pieces) 4 pieces adapter converter: 1/2" --- --- female square converted to 3/8" male 3/8"------ female square converted to 1/4" male 3/8"- ----- square female converted to 1/2" male 1/4"------ square female converted to 3/8" male Plug adapter 3 pieces: Length 1/4*1/4*65mm ------ 1/4" shank can be converted to 6.35mm square head Length 3/8*1/4*65mm ------ 1/4" shank can be converted to 9.4mm square head Length 1/2*1/4 * 72mm ------ 1/4" shank can be converted to 12.6mm square head MaterialSteel High carbon steel, high quality material 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 located at the drive end adapters and reducers lock onto the drive shaft. convenience no matter which tool you choose to use. Ideal for DIY, household maintenance and most general repairs High QualityExtension adapters are made of heat treated chrome vanadium steel with a black oxide coating. Adapters and reducers are premium high strength chrome plated steel with a manganese phosphate coating to help resist rust and corrosion. a lifetime of use. Widely ApplicationSuitable for 1/4 inch quick change chuck systems or directly into the drill chuck. Any cordless electric drill in a nut driver. Convenient for quick driving of nuts, bolts and fasteners etc. The spring-loaded ball bearing on the head holds the sockets properly.