Second Nikon F with many improvements over the Nikon F of 1959-1969
Nikon F2, 1971-1980, some say may have ended in 1981 because numbers 805xxxx is 1980, but, there are some 806xxxx bodies also, they may have been made in 1981.

Swing open back
Meter Battery in the Camera, turned on by slightly moving advance lever... Like the Nikon FM/FE
New shutter with 1/2000 top speed, with any intermittent speed from 1/125-1/2000 (green)
Trigger moved to the front of top/right deck
Self-Timer has 2s-10s long exposure times added
Frame counter is now under the top plate in front of the wind lever, instead of "IN" the wind lever.
Shutter Cocked indicator is in the center of the shutter speed dial, instead of in front under the top plate
Advance lever has a shorter throw plus a plastic tip
Flash Sync output is moved to the front of the camera, on the front/left cover plate
many internal improvements