“Set includes — 4 x 1/4”, 2 x 3/8" and 2 x 1/2" drive with 1/4’’ hex shaft shank. Two 1/4 (F) to 3/8 inch (M) and 3/8 (F) to 1/2 inch (M) adapters, and two reducers in 3/8 (F) to 1/4 inch drives (M) and 1/2 drive sizes (F) to 3/8" drive (M). Quickly adjust lag bolts and hex head screws. High Quality — The extension adapters are made of heat treated chrome vanadium steel with a black oxide coating. The adapters and reducers are premium high strength chrome plated steel with a manganese phosphate coating to help resist rust and corrosion and ensure a lifetime of use. Usage General Use — This Hex Shank Screwdriver Extension Bar Set is designed to meet a variety of needs. Fits perfectly into the chuck or manual screwdriver. Comprised of your most common drill bit sizes of 1/4", 3/8" and 1/2", varying sizes for shanks. Provides versatility and convenience no matter which tool you choose to use. Ideal for DIY, household maintenance and, more generally, r Purpose — This adapter set