From the A-sylum to the E-sylum! just acquired, an approximately heller/groschen/pfennig-sized token from the Klosteneuburg Irrenanstalt, alternatively the Lower Austrian "State Lunatic Asylum" at Klosterneuburg, an establishment which was active from c.1869/70 to c.1920/22. Whether the denomination of the piece equated with any of those monetary units is anybody's guess; the unit of currency may just have been internal. The actual diameter is just under 18mm and the design is the same on both sides.
Amongst the various information available about the issuer online, almost all in German, is this fairly reasonable translation:
How appropriate for numismatic bibliomaniacs! This is the first lunatic asylum token I recall seeing. Are there others out there? Tokens are like cockroaches - if you see one, there are usually quite a number more where that one came from.