This socket is made specifically for the 17mm hex on the Hewland and Webster (and other VW-based) gearboxes. Accepts any 3/8" drive ratchet or extension for easy access to the drain and filler plugs.
Note: VW recently added a "tamper-proof" nipple in the middle of the hex on their drain plugs (we do not carry this style plug). If you have the later style tamper-proof plug, you will either need to grind the nipple out of the plug, or drill a matching hole in the hex on this socket.