Neal,

You only need two pieces - the plastic 6-pin female socket housing and its back cover. You will transfer the original wires with the female pins attached from the old socket to the new.

I can't say for sure whether the back cover is included in that part number. The cover itself does have a number stamp (23721). Maybe PartsShop can answer your question, or simply specify that you need the back cover when you order the socket.

Good luck,
Barrie