Aristo 623 circular slide rule full set 1962 Germany

This round slider rule is marked Aristo 623 and comes in it’s original leather signed sleeve and with it’s manual in French (marked 1962). Made for easy and simple calculating of percentages for discount on bulk sales as well as interchanging foreign weights and sizes. Fully functioning with complete cursor  and in good condition, only small signs of use or age (some darkening to the yellow). Original leather pouch is marked Aristo also and it still contains the control slip (so not used much). Diameter of the disk is ca. 12,5 cm or 5 inches. Check the below video on how to work your vintage man tool : slide rule operation instructions!