Made from 1951-1962 the Viso 1 is a reflex housing for Leica M camera bodies and screw mount lenses.The Viso housing has a mirror and ground glass focusing between the camera body and either special short Viso mount lenses, or the lens heads of various rangefinder coupled lenses.The LVFOO is a 5x magnifier.Weights 1 lb 1.9 oz.