Input Drive Size: 3/8" Drive Shape: Square Length: 53.5mm Type: 12 Point Whitworth Universal Socket Output Size: 5/16" Opening: 12pt Product Dimension (Refer Line Drawing Image): D1 Size: 20.8mm D2 Size: 19mm H Size: 12.8mm L Size: 53.5mm 3/8 Sq. Dr. Universal Socket Whitworth 5/16 12 point Length 53.5mm