Original German Map Reader Kurvenmesser in Box

Decent, used condition German map reader which is possibly post war made, I am not sure on this one. Simply trace a path along a map and the dial will show you the distance traveled. Great map case accessory. The box has a German and an English label. The construction and look of the map reader is more war time/pre war compared to post war ones I am familiar with but that doesn't rule out early post war manufacture. This was a very popular export item basically as long as it has been produced and it is not to unusual to see it with English instructions even if it was made in 1925. The USA was a fairly big market for these. Fairly good condition. One spot of wear / corrosion on the bottom area.