Luftwaffe Flight Navigation Computer “Dreieckrechener”

In a nice used condition a Luftwaffe Flight Navigation Computer (Dreieckrechner). A manual flight navigation computer which were basically a circular slide rulers to assist in navigation calculations. It does have a diameter of 15cms and is nicely maker marked by the company “Dennert & Pape Hamburg-Altona” and April 1941 dated. A nice original example in used but good condition!