Vintage Rare 1947 K & F N4080-3S Log Log Duplex Trig Slide Rule w/ Leather Case

Vintage Rare 1947 Keuffel & Esser N4080-3S Log Log Duplex Trig Slide Rule w/ Leather Case Pre-owned in excellent condition with minimal wear & tear. MINT!!!! Description: This ten-inch double-sided mahogany rule is fully covered with white celluloid. On one side, there are L, LL1, DF, D, LL3, and LL2 scales on the base and CF, CIF, CI, and C scales on the slide. The top of the base is marked in red: KEUFFEL & ESSER CO. N.Y.; PATS. RE.20,984 1,930,852 2,168,056 2,170,144 PAT. PEND.; MADE IN U.S.A. The right end of the slide is marked with the model number: < 4080-3 >. On the other side, there are LL0, LL00, A, D, DI, and K scales on the base and B, T, ST, and S scales on the slide. The left end of the slide and the front left corner of the base are marked with a serial number: 758445. The indicator is glass with plastic edges held together with metal screws. It comes with slide ruler, instruction manual, original leather case & box. Please refer to the pictures. What you see is what you get.