ITAB Styropor BASF Vollwarmeschutz pocket magnetic slide rule sleeve 1970 Germany

This interesting build pocket slide rule is made by ITAB from Germany, specially for calculating heath savings by using the BASF-styropor product. ITAB does not use numbers but gave it the name Styropor-Vollwarmeschutz. It has dedicated scales and a simple cursor. What makes this rule special is that the slider does not run in grooves but is held in place magnetically. It comes in a generic unsigned plastic sleeve with the original manual in German, complementary to the back of the slide rule. The case and slide rule are all complete and in very good condition with signs of use and age (some staining under the slider). The scales are cover by a layer of see-through plastic, making sure it will never fade. It is a little different design to this ITAB Styropor I sold before.  The slide rule measures 16 cm or 6 1/4 inches. Check the attached video on how to work your vintage man tool: slide rule operation instructions!