VEB Mantissa artillery slide rule case 1970 GDR Germany

This bicolor full plastic slide rule comes in it’s original grey box. There are no makers marks nor army designations. It has scales on both sides. It was made by VEB Mantissa from the GDR/DDR (Eastern Germany) so there was no need for commercial logos or designation. This was provided to the artillery crew of the army to calculate shooting angels through distance and elevation calculations. Nice touch is the small fixed cursor on the back. All scales are designated with a number for easy instructions (not available). It measures 30 cm or 12 inches. It is in very good condition with minimal signed of age and use. Do check the attached video on how to work your vintage man tool : slide rule operation instructions!