Viewer for the format 6 x 13 for photos and slides. Fine wood, beautiful, big, big. ocular, focusable and adjustable distance from the eyes. Folding mirror and focusing screen. Company A. Mattey, Paris, founded in 1872, produced a variety of stereoscopic, monocular stereoscopic observers and accessories. Mattey was the innovator and the world's largest manufacturer of stereo observers. Its products have been sold under different brands and offered by retailers across Europe. Of all the brands,"" Unis France"" label is most often used. The catalog 1932 and has 77 pages.