Keuffel Esser 4081-3 Duplex DeciTrig slide rule case 1950 USA

This is a quality build pocket slide rule with elaborate calculation options through 21 different scales. This great rule also come in the original signed brown leather case. This K+E rule is in good condition, with only signs of normal use, the ivoride seem to have darkened a bit on the entire slide rule, both sides or perhaps just a bit darker batch? It is made of bamboo with a Ivoride white plastic cover and with metal ends and partial metal cursor. This full size 4081-3 model Duplex Decitrig is the predecessor of the 4181-3 all ivoride model. Itmeasures ca. 32 cm or 13 inches wide. Check the attached video on how to work your vintage man tool : slide rule operation instructions!