The Fokker C.X was designed in 1933, for scouting and lighter bomber purposes. The Finnish Air Force was a big customer with 39 frames (the aircraft was also license-built in Finland). the Royal Netherlands Air Force took 20 frames and the Royal Netherlands East Indies Army Air Force took 13. The Republican Spanish Air Force seemed to have 2 delivered to them. The Dutch ones were somewhat succesful in their missions, but after the German attack in May 1940, only 2 frames managed to escape to France. Unfortunately I do not know the serial of the aircraft in this photo.