Periscope, Type M6, for Armored Tanks Sherman, Stuart C-119 operates in the same manner

operates in the same manner but has greater air volume capacity for larger aircraft with more air-driven instruments such as a heavy bomber or transport

BT-13 Valiant

In this specimen

The attitude control switch has a metal guard which prevents it from being switched off

likely indicating a manufacturing year of 1950

Periscope, Type M6, for Armored Tanks Sherman, Stuart C-119 operates in the same mannerHere is a fine specimen of the Periscope, Type M6, as used in US WWII era armored tanks such as the Sherman and Stuart. From the website The Sherman Tank: " there were 12, M6 periscopes in each late model Sherman. Six mounted in in various places, one in the drivers hatch that rotated, and a fixed one in front of him. The co driver had the same layout, just on the other side, he used the hatch or fixed periscope to aim the bow machine gun. The loader