K&E Slide Rule with Case excellent condition

This item is a vintage Keuffel & Esser (K&E) slide rule, specifically likely a N4081-3 Log Log Duplex Decitrig model, which was manufactured in the United States.  Item Type: Mechanical analog computer used for mathematical calculations.  Era: Popular in engineering and education during the mid-20th century, particularly around the 1940s-1960s.  Components: Includes the slide rule itself and its original orange leather protective case.  Value: As a collectible, vintage K&E slide rules vary in price based on condition, model, and included accessories.  This one is in excellent condition including case.