This vintage Masoneilan slide rule is a must-have for collectors and enthusiasts of engineering and science memorabilia. Made in the United States, this slide rule is perfect for those interested in the history of technology and innovation. Measuring 8.5 inches, it is a great addition to any collection of slide rules and engineering instruments. With its precise measurements and clear markings, this slide rule is perfect for both educational and recreational use. Whether you are a collector or an engineer, this vintage slide rule is sure to impress.