Find explanation for the Technolgy of binoculars at KuSeRa
Amazon.com : Brass Nautical Antique Working Telescope/Spyglass Replica in Leather Box, with Glass Optics, Extendable to 16 inches, Made of Pure Brass, Decorative Kids Scope : Electronics
Original German WWI & WWII Panoramic Artillery Telescopic Gun Sight by – International Military Antiques