Still working - Missing the screw loop at the top. Opisometer on one side, compass on the other side. Please satisfy yourself with condition through the images. The Vintage Opisometer (Curvimeter) is a unique and rare scientific instrument that measures distance on maps and nautical charts. Dating from 1951 to the present, this collectable piece is a testament to the history of navigation and cartography. Made from a mix of materials, this instrument is a valuable addition to any collection of scientific tools or vintage navigational aids. Its compact design and functionality make it a functional as well as a decorative item for enthusiasts of old-world navigation.