Hello Jsaen, this type of watch was made around the 1930's by numerous watch manufacturers. Zenith,Omega , Breitling,Helvetia, Rellum and many more. They were popular amongst early pilots after WWI and its mentionned they
were used by the Luftwaffe pilots in training schools. The Czechoslovakian army issued Zeniths to their pilots during WWII. The mystery is why did all these manufacturers make this type of model. Were they popular in the beginning and every manufacturers wanted to profit from the fad or was it a special order made by a government.
I have two of the three models made by Zenith. The third one has a subdial.
As you can see I have some sort of an obsession for this model: