The Vintage Keuffel & Esser Co 18 Inch full and half Drafting Paragon Ruler is a collectible drafting tool dating back to the mid-20th century. The 18 inch length is harder to find. This ruler, made by the renowned brand KEUFFEL & ESSER, is a precision instrument designed for engineering and scientific applications. The 18-inch size and intricate design make it a desirable item for collectors of vintage drafting tools and enthusiasts of scientific and engineering history. The ruler comes in its original box, adding to its authenticity and value as a sought-after piece for those interested in the history of drafting and measurement tools. Has some slight wear from usage.