IWA 0675 Wasserrohr-Rechner SR 722 Ma slide rule 1974 Germany

This slide rule was made by IWA, model 0675 in German, this version is copyrighted 1974. It is a design by H. Rötscher but it also has the earlier SR 722 Ma number on it with reference to the AWF so it seems to be a design that stood the test of time and this is the last incarnation. It has many possible calculation concerning water pipes. Fortunately it does not only has a manual on the back, but it also comes with the original full manual, both in German. It also comes with the original black sleeve. It is in very good condition with hardly any signs of use or age. It is fully functioning with all parts intact. It measures ca 21 cm or ca. 8 1/4 inches long. Check the attached video on how to work your vintage man tool : slide rule operation instructions!