Trench Periscope 10x20 DOW (​Waffenwerke Bruenn, Prerau Plant, Czechoslovakia), circa 1942

Grabenperiskop (trench periscope), produced and marked DOW, or Waffenwerke Bruenn, Prerau plant, Czechoslovakia (renamed Opticotechna GmbH, Werk Prerau in 1943), in around 1942 and intended for the Wehrmacht scout troops and Scharfschütze shooting positions.

The periscope is made up of a tube with a length of 53 cm, which allows and guarantees the observer a periscopic vision in total safety. At the ends of the tube, there is a 10x eyepiece equipped with a graduated reticle between -60° and +60° and a 20 mm objective lens.

A very rare original vintage photo shows its use.

History of Waffenwerke Brünn

The company began as Československá zbrojovka Brno, one of Czechoslovakia's leading arms manufacturers between the two world wars. After the German occupation in 1939, the plants were incorporated into the Reich's war industry and renamed Waffenwerke Brünn AG.

The company operated several factories, each identified by a different code:

dot: Brünn (Brno)

dou: Bystrica

dov: Vsetín

dow: Přerov (Prerau)

dox: Podbrezová

The Přerov factory (DOW) was not the main producer of Mauser rifles like the Brno site (DOT), but it was involved in the production of military components and optical equipment. In 1943 it was reorganized and renamed Opticotechna GmbH, Werk Prerau/Protektorat, while continuing to use the dow code on some military production.