Gillette Bottom Dial
Gillette officially called them the 195 Adjustable Razor, but shaving enthusiasts nicknamed them the Bottom Dial. They are the rarest and most sought after of the Gillette adjustables. Gillette sold a batch in late 1960 (F4) for the whopping price of $1.95, so I'm guessing a Christmas 1960 "special". This is one of those.
The initial Bottom Dials were only prototypes and they were sent out for feedback. The adjuster dials were numbered up to 5 with half notches between them. The feedback was that men preferred the adjuster dials at the top.
How does it shave:
Its a pretty mild shaver. It has the same head as the F4 Toggle so the shave is the same although I do prefer the balance of the Bottom Dial.