FABER CASTELL slide ruler Model 398 Dynamo Original 1970s in it's box 

measuring woodworking carpentry Electrical & Mechanical Engineers

° Slide ruler in laminated wood stock,

° Measures approx cm 29.5 x 4.

° Inside the ruler is written "Dynamo", "398 Faber Cstell D.R.G.M."

In it's box, well kept by collector.