An important development, the Gundlach rotary periscope, incorporated a rotating top with a selectable additional prism; this allowed a tank commander to obtain a 360-degree field of view without moving his seat, including rear vision by engaging the extra prism.
An important development incorporated a rotating top with a selectable additional prism. The Gundlach rotary periscope was an important development. This allowed a tank commander. This was to obtain a 360-degree field of view without moving his seat, including rear vision by engaging the extra prism.