1. Although there is no indication of maker on the rule it is a Faber Castell.
2. The rule has a scale of centimetres in the well. Using this tells you the distance from the left hand end of the stock to the right hand end on the slide.
3. Comparing this with the Nestler 0123 shows the difference in interpretation of the word "Rietz". The Nestler has K, CI and L scales in addition to the ones on this rule.
4. Rear of slide rule has marks on stock to allow use of trigonometrical functions without need to remove slider.
5. Table of conversions on rear