K. & E. Deci-Lon Slide Rule (1947, 1961)

Keuffel & Esser Co. - New York
Scales: A/B/C/C1/C1F/CF/D/D1/DF/K/ Ln0/Ln1/Ln2/Ln3/Ln-0/Ln-1/Ln-2/Ln-3/S/SRT/Sq1/Sq2/T
Overall length: 12.75 inches (Ruled portion = 10 inches)