The kit includes --- 4 1/4" screwdrivers, 2 3/8" screwdrivers and 2 1/2" screwdrivers with 1/4" hex shank. Two 1/4" (F) to 3/8" (M) and 3/8" (F) to 1/2" (M) adapters and two 3/8" (F) to 1/4" (M) and 1/2" (F) to 3/8" (M) reducers. The set screws and hex head screws can be quickly adjusted. HIGH QUALITY --- The extension adapters are made of heat-treated chrome vanadium steel with a black oxide finish. The adapters and reducers are made of high quality, heavy duty chrome steel with a manganese phosphate coating to help prevent rust and corrosion and ensure a long service life. UNIVERSAL --- This hex screwdriver extension set meets a wide variety of needs. Fits perfectly into a chuck or manual screwdriver. Includes the most commonly used 1/4 inch, 3/8 inch and 1/2 inch bits with varying shank sizes. No matter what tool you choose to use, it offers you versatility and convenience. Ideal tool for DIY, home maintenance and general repairs. Uses --- This adapter kit is designed to provide a