Rare Nitsche & Günther patent “Ultrasin” goggles

Rare Ultrasin goggle or Ultrasin-Gläser which are almost identical to the Umbral goggles from Carl Zeiss. These Ultrasin goggles are patented by Nitsche & Günther, Rathenow and this example has been produced by Merz-Werke, Frankfurt a.M.-R. Spezial-Fabriken. This is a rare variant patented and produced by a different company than 95% of the encountered examples. The goggles are in mint condition complete with manual and their original pouch.