Controller 75 R mini circular slide NOS rule full set 1960 Germany

This smallest version Controller is New Old Stock (NOS), never used, complete with controller slip and manual in German. These were made specially as a marketing tool for the German Foundry called Friedrich Krupp. Both slide rule and pouch show the logo, they were never issued and came to market in a small batch (I have several). It is a high quality aluminum circular slide rule MOD. 75 R version, measuring 7,5 cm or 3 inches in diameter. You can find the largest 200R version here. Everything is in great condition, needly packaged in a small plastic holder. The slide rule is fully functioning with all parts intact. Check the attached video on how to work your vintage man tool : slide rule operation instructions!