Not met that one before, but the price (at $27 including postage to UK) compares well with that of the
dialgizmo, albeit uncased. I see no mention of speed dial facilities such as those of the dialgizmo, so it depends whether these are important to you.
Although it comes without a casing, it looks as though it would be small enough to mount inside the pattress of a flush-mounting telephone socket.
If you fancy giving one a try, I'd be interested to hear how you get on.