VINTAGE DIETZGEN 1/4” Scale Blueprint Measuring Drafting Tool + Box RARE 1715-4. I used this for years to pull measurements of of blueprints for bidding and takeoff sheets for ductwork lengths. Used it during my 30 year career and it still works like brand new. The wheel at the bottom rolls along you blueprint and matches the scale to provide an automatic accurate linear footage count without damaging the prints
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