This vintage collectible Keuffel & Esser slide rule is a true gem for anyone interested in engineering, science, or collecting. With its 11-inch length, it is a perfect addition to any slide rule collection. Made in the United States, this slide rule is a testament to American craftsmanship. It is a great tool for anyone who wants to do precise calculations in a stylish and classic way. Whether you are a seasoned engineer, an aspiring student, or a collector, this slide rule is a must-have.