Introducing the hex socket: 6.35mm hex. One head is a 2-hole, two-slot SDS shank, the other is a hex socket. The 60mm black knurled models can handle higher torque, and the 60mm and 70mm silver models have no knurling. High Quality Material: Chrome vanadium steel, fully formed quality, durable and reliable. Chrome vanadium steel suitable for heavy duty impact screwdrivers. Spring-loaded ball bearing on head to hold sockets securely. Easy to use: The flexible shield protects the hand from injury when the inner rod rotates. Use a drill bit to bend, twist and turn in a confined space. Product use: It can convert electric hammer, impact drill and other original SDS connection methods into internal hexagonal connection method, so it can connect all kinds of drill heads, chamfer tools, drill bits and other hex shank tools. Wide Application: Ideal for woodworking, carpentry, auto parts repair, etc. Nice gift for a handyman. Characteristics: Colors: Black and Silver. Inner Hex Size: 6.35mm.