This is optional AE Motor Drive FN for the Canon F-1n's.  It is capable to achieve five frames per second and able to rewind a roll of 36 exposure film within eight seconds.  Beside that, the Motor Drive would add additional shutter priority AE feature to the camera.  The motor and poer source comes in seperate modules, and there were four power sources available.  The unit that I have here is with eight-AA batteries holder!

Canon AE Motor Drive FN