Set includes --- 4 x 1/4", 2 x 3/8" and 2 x 1/2" screwdrivers with 1/4" hex shaft. Two 1/2" 4 (F) to 3/8" (M) and 3/8 (F) to 1/2 inch (M) adapters, and two 3/8 (F) to 1/4 inch (M) and 1/2 drive size (F) to 3/8" (M) Quick install lag bolts and hex head screws. extension is chrome vanadium steel heat treated with a black oxide coating.The adapter and reducer are premium high strength chrome steel with a manganese phosphate coating to help prevent rust and corrosion and ensure longevity. Universal --- This Hex Handle Screwdriver Extension Set is designed to meet a variety of needs Ideal for chucks or handheld screwdrivers Contains all sizes of 1/4", 3/8" and 1/2" most common bits, with different sized shanks. Whichever tool you choose to use, it offers versatility and convenience. Ideal for DIY, home maintenance and, more generally Purpose --- This adapter kit is designed to provide a secure locking extension to your existing tools. Provides extra length to access many hard-to-reach spaces. A spring-loaded ball lock ensures a snug fit on the driver\s head to prevent slipping during use. Specially machined to fit securely in hand screwdrivers, drill wrenches or impact wrenches. ball bearing ch After-sales service --- We will provide you with the most friendly customer service. Don\t hesitate to contact us If you have any questions about the Drive Socket Extension and Adapter Kit, simply contact customer service for help, parts, replacement or refund