2X 1/4" Square to 1/4" 6.3mm Hex Female Screwdriver Bit Adapter Holder Socket
It is used for screwdriver bit, socket adapter,step drill,chamfer converter. 6.3mm series screwdriver head connector. 2 x 1/4" square hole to 1/4" hex converter. Size:1/4" square hole to 1/4"(6.3mm).