Keuffel & Esser Slide Rule 4083-3 Log Log Duplex Vector Vintage Engineering Tool **Keuffel & Esser Co. Slide Rule 4083-3 Log Log Duplex Vector** This vintage Keuffel & Esser slide rule is a classic engineering instrument from the mid-20th century, perfect for collectors or enthusiasts of historical calculating tools. While it shows significant signs of its history, including personal markings from its time at RCA Service Dept, it remains a functional piece of mathematical history. - **Brand:** Keuffel & Esser Co. (K&E) - **Model:** 4083-3 Log Log Duplex Vector - **Material:** Mahogany wood core with celluloid faces - **Scale Types:** A, B, T, ST, S, D, DI, K, L, C, CI, CF, CIF, DF - **Included:** Original leather carrying case with belt loop - **Origin:** Made in USA This is a pre-owned item that can have wear or imperfections; please review the photos carefully. The leather case has significant wear, scuffing, and ink markings (including "RCA SERVICE DEPT"). The slide rule #Retro