You receive 2 face plates, one 4" and one 6". Both are threaded 1"-8 Tpi. The Shopsmith 5/8" - 1"-8 Tpi is included.
Priced separately the cost would be around $85.
These items are not Shopsmith brand. But using the adapter makes the faceplates fit your Shopsmith perfectly. The adapter can also be used with 1"-8 Tpi lathe chucks..