U.S. Army Equivalents & Abbreviations Ruler In Leather Wallet - Nice Used Condition

A nice used example of an adjustable ruler made by Keuffel & Esser co. New York. Marked with Equivalents & Abbreviations in order to calculate distances and weights for example from yard to meters, KGs to LBs and Inch to CMs. The ruler comes in original leather and U.S. patented wallet. Hard to upgrade.