ITEM NAME:8PCS Socket Bits Adapter Set Hex Drill Nut Driver Power Shank 1/4" 3/8" 1/2 #gib Store Home Promotion Hot Item Add to Fav.1/4 1/4 50mm length---1/4 " shank can be converted to 6.35mm square head. 3/8 1/4 50mm length---1/4 " shank can be converted to 9.53mm square head. 1/2 1/4 50mm length---1/4 " shank can be converted to 12.7mm square head.