movements used in tudor classic watches are manufactured by the swiss companies eta or valjoux. in 2015, tudor launched its first in-house movement for its pelagos and north flag watches. in 2017, tudor then entered into a cooperative agreement with breitling, providing the mt5612 movement for breitling's superocean heritage watch, while in return breitling produces the tudor calibre mt5813 movement for use in the new tudor heritage chronograph, based on the breitling b01.