The Classique Tourbillon Extra-Plat 5377 from Breguet features no less than 4 different distinctive horlogerie features, including "Clou de Paris" for the hours and minutes chapter, barleycorn for its edge, strait chevrons for the power-reserve indicator and each element with a cross-hatched border.
The silicon balance spring and the specially developed escapement housed in the Classique Tourbillon Extra-Plat 5377 enable the balance of its calibre to reach the frequency of 4Hz, which is high for a Tourbillon balance.