During W.W. II, US Army tanks carried panoramic periscopes, so they could maneuver securely, without exposing the driver in battle.
Packed in its original issue carton, each prism is housed in an army brown metal frame. Glass prism measures 54mm x 38mm x 146mm, Pkg. weight 2 lbs. Original value to U.S. Government was $50.00 each in 1944