This device is a special- purpose slide rule developed for the navigation of aircraft. This particular one comes from the (ex-) Soviet Union and, as such, all the scales are in Russian.
Construction of the rule is quite cheap and consists of plastic laminated to very light (probably pine) wood. The cursor is transparent plastic nailed (yes, nailed) to wood edge- pieces. It's a little under a foot long and a little over 1-3/4 inches wide. It is an excellent example of the fact that one does not need to have "the best of everything" to do a job.
Scales on the front (Thanks for the translation, Sergej!) are : Distance, Speed, Altitude, Bearing, Corrected Airspeed, and Temperature.
Scales on the reverse include: Corrected Altitude, scales for time conversion, and sines and tangents.
Images of the front and
back of the rule are available.
Note that these are large images (434 and 359 ko, respectively) and were
scanned at 300 dpi and despeckled so the details are all clearly visible.
You could even print them out and make your own!