Introduction of the hex socket: the hex is a standard size of 6.35 mm. One head is a two-slot 2-hole SDS shank, the other is a hex socket. The 60mm black knurled models can handle more torque, and the 60mm and 70mm silver models have no knurling. High quality material: chrome vanadium steel, integrally formed , durable and reliable quality. Chrome vanadium steel suitable for heavy duty impact screwdrivers. Spring-loaded ball bearing on head holds sockets securely. Easy to use: Flexible shield protects hand from injury when internal shaft rotates. Use a drill bit to bend, twist and turn in a confined space. Product use: It can convert an original electric hammer, impact drill and other SDS connection method into an original SDS connection method. internal hex connection, so it can connect all kinds of drill heads. drills, countersink tools, drill bits and other hex shank tools. Wide Application: Ideal for woodworking, carpentry, machinery and auto parts repair, etc. Nice gift for DIY