: ? Vintage Keuffel Esser K E Slide Rule w/ Leather Case Math Engineering Tool Step back in time with this vintage Keuffel Esser slide rule, complete with its original tan leather case. A true collectible for math lovers, engineers, architects, and vintage tool enthusiasts. This piece highlights mid-century craftsmanship and precision design, making it perfect for display, teaching, or gifting to a collector. Brand: Keuffel Esser (K E) Type: Slide Rule with conversion tables formulas Material: Metal plastic with leather case Era: Mid-century vintage Condition: Good pre-owned vintage condition, light wear consistent with age Perfect for: Engineering collectors, STEM enthusiasts, office decor, or retro gift I ship Monday, Friday, and most Wednesdays. Have a fun time shopping! ? vintageengineering ? vintagetools ? midcenturydecor ? mathnerdstyle ? retrooffice This is a vintage Keuffel Esser (K E) slide rule, a classic tool for math and engineering calculations. It comes with its original leather case, which provides protection and adds to its vintage appeal. A great collectible item for engineers, mathematicians, or anyone interested in vintage scientific instruments. Don't miss the chance to add this unique piece to your collection!