Its a router bit made by Kreg, and I assume other companies Yonico Whiteide and etc
Its part of a two piece set (if your a cheapskate like me) and dont buy the complete jig.
As it happens the Sommerfield Brothers both have a system one router based and the other table saw based.
I tried to attach the documentation but it exceeeds the 5Mb limit so continue via the link.
https://www.kregtool.com/shop/routing/routing-system-components/precision-beaded-face-frame-system/PRS1200.html