Breitling watches are made in Switzerland using Swiss components. Breitling makes two movements: the calibre B01 and calibre B04, a B01 with an added GMT module. ETA and Valjoux are the primary suppliers of ébauches used in certain Breitling watches. The ébauches are completed in the Breitling Chronometrie Workshops before undergoing COSC (Contrôle Officiel Suisse des Chronomètres) certification.