Grumman designed the F4F Wildcat and it became the primary fighter for the Navy in the early days of WWII playing an instrumental role in the Battles for Wake Island, the Coral Sea, and Midway. Starting in 1943, though Grumman held the production rights, they had others build them.
General Motors Eastern Division produced the FM-1 Wildcat, identical to the Grumman F4F-4 Wildcat, and the FM-2, which is based on a Grumman prototype designated XF4F-8. General Motors specifically made FM-2s for small carrier operations. They featured four wing guns, a slightly taller tail fin than the previous models to handle the torque, and a more powerful engine - a Wright R-1820-56 engine (1,350 hp).
This aircraft is an FM-2P because it has been fitted for photoreconnaissance missions. Its flaps are vacuum operated, its under carriage is hand cranked, and the only hydraulic system in the aircraft is the brakes.