DescriptionFlexible curve rule, 57 2817-18, made by the Keuffel & Esser Co., (Hoboken), no date, circa late 1950s-early 1960s. Plastic and metal, straight length 18" x 7-8" wide x 18" thick. A typical item used in drafting work. This item would formerly have had the stock number 1924-18. K&E had their main office and factories in Hoboken until December, 1968.