Rolbart made a number of sharpening devices for safety razor blades. They were a German company and these products were made from the early 1900's. This model is in great working condition, with all levers, cogs, cams and barrels working nicely. The blade seats nicely on the rollers and I would say it is in great usable condition, certainly as a working showpiece!
These devices were designed for use on carbon steel blades, so it might come in handy if you use old carbon steel vintage blades, but less so (if at all) on modern stainless blades, which also have modern material coatings over their edges.
a Nice piece piece of history but don't count on it to take your shaves to zero cost for blades without giving up some comfort in the process!