This stereo viewer prototype was invented and developed by Brian May, who owns a large collection of stereo views, stereo technology and ephemera. Brian May also acquired the copyright for the London Stereoscopic Company - one of the largest and most popular stereo companies in the 19th century, The OWL viewer, which this is a prototype of, is used to view modern and historical stereo views. The ingenuity of the viewer is that it can be folded flat, for ease of transportation.