Stadimeter Mark III in Leather Case, US Navy C-47 Mark II-C consists of a

Mark II-C consists of a battery-powered/illuminated sighting scope with interchangeble filters for overcoming the difficulty of seeing the ground through smoke

for dual engine aircraft of the US Army Air Corps during WWII

and possibly others

A synchroscope informed the pilot or flight engineer whether or not a pair of engines are turning at the same RPM's

Above that limit

Stadimeter Mark III in Leather Case, US Navy C-47 Mark II-C consists of aThis is an original WWII era Stadimeter Mark III as used aboard ships of the US Navy. A stadimeter is a rangefinder, used to determine the distance from the user to an observed known target. By viewing the target through the device and turning the knob until the presumed height of the known target is bracketed between the upper and lower limiters in the viewfinder, one can then read the distance of that target on the corresponding height on the side