Easily adds a locking keyless chuck to any 1/4-Inch hex drive tool.Allows use of locking steel keyless chuck, 1/2-Inch-20 UNF thread to 1/4-Inch hex, to utilize any standard shank drill bits 1/16-Inch-1/2-Inch sizes and accessories.Use no.3 Phillips screwdriver to secure chuck with left-hand thread screwIsomax contractor quality