Loga 30 Tt circular duplex slide rule in case 1950 Switzerland

This high quality metal double sided circular slide rule was produced by Loga from Switzerland. This model Tt comes with the original leather case that has kept it in good condition so there are minimal signs of use or age, (name written on inside of the case). It is fully functioning with good working cursor on both sides. The diameter of the slide rule is 12,5 cm or 5 inches. Check the attached video on how to work your vintage man tool : slide rule operation instructions!