Stainless steel locking ball ensures secure fit. sockets snap on tightly won't slip off. 1/4" (6.35mm) hex shank prevents stripping during high speed drill operation. Super strong heat treated chrome vanadium steel for normal impact. Use sandblasted finish. Applies to the screwdriver handle or electric screwdriver tools (hexagonal hole or three jaw chuck can be). Driven sleeve is used, can be the original hexagonal side after installation on size into square size, which can be used for the installation of the sleeve, is a good accessories to convert. Size: 1/4"*1/4"*50mm(Length) 1/4 "shank can be converted into 6.35 mm square 3/8"*1/4"*50mm(Length) 1/4 "shank can be converted into 9.53 mm square 1/2"*1/4"*52mm(Length) 1/4 "shank can be converted into 12.7 mm square Material: Chrome vanadium steel CR V. Package List: Socket Adapter Hex Shank Set(Include 3pcs)