Tool connection 3474 Socket Set - Whitworth 3/8"D 7pc ( Laser ) Popular on Classic cars. Sizes include: 1/8" | 3/16" | 1/4" | 5/16" | 3/8" | 7/16" | 1/2" | 9/16" | 5/8". Supplied on a socket rail. 3/8"D. Manufactured from Chrome Vanadium.