MaterialSteel High carbon steel, high quality material to be avoided during use.General Use These extenders, adapters and reducers are designed for Impact use and feature spring-loaded detent balls to lock sockets securely, while through-holes at the drive end of 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 repairsHigh QualityThe extension 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. Spring-loaded ball bearing on head holds sockets properly.Color:BlackFeature:1. Color coded for easy recognition.2. Spring-loaded ball for secure grip retention, so sockets snap into place and won't slip.3. The 1/4 inch hex shank prevents stripping during high speed drilling operation.4. Extra strong heat treated chrome vanadium steel for normal and impact use5.Adapts sockets to drills and drivers, turns any electric or cordless drill into a nut driver.> 6. Converts all power drills into speed plug drivers.7. Use with a hand held screwdriver or a battery or power tool.Material: Chrome vanadium steel (CR-V)Size:1/4*1/4*65mm Length ------ 1/4" shank can be converted 6.35mm square head3/8*1/4*65mm Length ------ 1/4" shank can be converted to 9.4mm square head< /p> 1/2*1/4*72mm Length ------ 1/4" shank can be converted to 12.6mm square headSet of adapters, 4 piecesSize:1/2"------ female square convert to 3/8" male3/8" ------ female square converted to 1/4" male3/8" ------- female square converted to 1/2" male1/ 4"------ female square converted to 3/8" maleNOTE:We offer a 30 day money back guarantee as well as a replacement guarantee of 12 months.luckymeetNote: The data is manual measurement, please allow 1-43cm error, due to differences between light and screen, there will be a certain color difference, the specific received in kind prevail.