German slide rule in small size 1950ties coal mine advertise

Description

German slide rule in small size 1950ties coal mine advertise
Model:
no factory brand on it
Construction year:
around 1950ties
Material:
wood and card board
Size:
5,55 inches
Condition:
excellent++ condition
Features and informations about this slide rule: You are bidding for a German slide rule. The slide rule is not marked with a special factory sign. On the backside its marked with an advertise of a caol mine company in Düsseldorf. The slide rule measures approximately 5,55 inches. Please ask if you need more informations. I am spezialist for vintage fountain pens, but not for slide rules. I try to answer as good as I can.