The first double-sided ruler, type 2/82 N is by Faber - Castell, made of Geroplast from 1962. For mathematics, physics, power, electro-technology and architecture. Mathematical calculations at a high level. The ruler is 38cm long 7cm wide and 1cm thick. The second ruler is a rare antique ruler, type No. 40 by Albert Nestler from 1940. Made of celluloid and mahogany wood. This ruler was for commercial calculations with scales known as the Kauffman scales. It uses scales to calculate the interest on capital over a number of days, discounts, conversions of units of measurement and exchange rates It can also be used for standard arithmetic calculations. The ruler is 29.5 cm long, 4cm wide and 1.5cm thick. Both rulers have a metal-framed glass cursor. Both rulers are in excellent and working condition. Items for the real collector. Shipment, will be carefully packaged with track & trace. Pick up is always possible.