By happenstance, a couple of years ago I won a CORFIELD Periflex «Focus Checker» aka «Focus Adapter» for a really good (low) price.
Except the correct nomenclature of the item, the seller was describing the item quite correctly, but nevertheless I was the only bidder, IIRC.
Here some links...
I am waiting for my XT-2 to arrive, hopefully this week. I am looking for a recommendation on what adapter to purchase so that I could use some of my Nikon lens with my new Fuji camera.
Thanks for the help.