This piece of equipment looks to have a long story, I actually rescue it and save it, it was part of a heating system (air conditioning) which was supplying only heat in to a truly large workshop.
The magic in this part is the over all construction, a base of Bakelite, atmospheric temperature measurement with out electronics, an true work horse capable to handle 10A at 220V.
Unfortunately I did not manage to rescue and the outside cover, probably lost in the years.
Enjoy those amazing pictures of an genuine European thermostat which is made with out expiration date in mind.
And regarding temperature accuracy, still perfect.
Another hard to believe information is that it manufacturer is still active in Austria.
The specific model is not in production, but the company is alive and kicking.
Fonovits Richard Ing Regeltechnik GmbH
http://www.fonovits.at/ Old catalog of 1978
http://www.ultimheat.com/Museum/section1/1978%20FONOVITS%2020111015.pdf