Very simple but beautiful watch.... Breguet 5907. The 5907 was made with two movements: initially with the Cal. 510 and later with the Cal. 511. The differences between the two are the power reserve (~72h on the 510 and ~95h for the 511), beat frequency (28,800 VPH on 510 and 21,600 VPH on the 511).
There is not much information about the two movements online, Cal 510 seem to be a JLC movement, Cal 511 is an F. Piguet movement that has been used both by Breguet and Blancpain (both Swatch's brands). I am assuming this is a Cal 511 based on the beat frequency + saw the same movement on a Blancpain Villeret ...
