Though unbranded, I think this is a Minerva single pusher chronograph with what looks like a 17j manual winding movement.
Circa 1930’s.
Case measures 38mm without crown.
20mm Hinged lugs.
Original multi colored dial with KILOMETRES A L'HEURE track measuring speed up to 300 Km/h.
Subsidiary dials for constant seconds and 30m register.
Very attractive and fully functional.