Antique Stereo-Viewer (Stereoscope, this is the original 3D) . The viewer is constructed of wood, metal, and glass and is in good age specific condition. The glass lenses are magnified and clear. There is a stag image stamped into the top of the metal part of the viewer along with model name “ Monarch”. The velvet lining that protects the face when you view is in fine shape as is the decorative etchings on the metal viewer. The wood handle folds out and the card holder slides to focus the card – all original no repairs or refinishing. It is stamped with Manufactured by Keystone View Co, Meadesville PA , PAT’D 1904 . This stereoscope would have been manufactured between 1904 and 1920 making it over 100 years old. This Stereo Viewer is used, sold as a collectible, as is, as shown. Examine the pictures closely as they are provided as part of the description The Keystone View Company was a major distributor of stereographic images, and was located in Meadville, Pennsylvania. Since 1892 Keystone produced and distributed both educational and comic/sentimental stereoviews, and stereoscopes. By 1905 it was the world's largest stereographic company, making the stereoscopes and placing double images on photographic cards that resulted in 3D when looked at through the viewer.