This is a cold war Radiation fall-out determination set for the Swiss Army. It contains a metal colorful slide rule with a diameter of ca. 11 cm or 4 1/4 inches, it is in hardly used condition and comes with the original vinyl red case. It is double sided and made of metal. There are is a hole on each side to aid the use. The plastic curser has a printed scale on it as well. The plastic yellow case holds a transparant stencil (marked 1976) to lay over a map to determine an area based on wind direction and speed. Besides the instructions on the case (French and German) there is also a paper instruction sheet (revised 1979). Â I am selling this set as I found (both items marked with the same name). There are signs of storage mostly on the yellow case but no damage. Check the attached video on how to work your vintage man tool : slide rule operation instructions!