A Zeiss prismatic rifle scope that was reportedly used on a very limited basis in the field during WWI.  This sight was noted for it's advanced optics.

See "The German Sniper 1914-1945" by Peter R. Senich, page 52.

Image of gew98_scope_prism-124.jpg

Image of gew98_scope_prism-125.jpg

Image of gew98_scope_prism-128.jpg

Image of gew98_scope_prism-127.jpg

Image of gew98_scope_prism-126.jpg

Image of gew98_scope_prism-130.jpg