Breguet, Type XX, flyback chronograph, Cal. Valjoux 225, 15-minute register, circa 1940s.
Difference between 30-minute and 15-minute registers.
Left : this watch, 15-minute register
Right : Valjoux 22, 30-minute register
The finger on the wheel of Valjoux 225 is a little longer in comparison with Valjoux 22. It forwards two teeth of minute register wheel in every minute.