Today, Tudor debuts the Black Bay Bronze. A new, larger 43 mm diameter version of the Black Bay, in a unique aluminum bronze alloy case. In addition to being the first Black Bay offered in a larger case size, and the first to have Explorer style hour markers (at 3, 6, and 9), it also represents the first Black Bay to feature the new in-house movement. Not to mention, it has pierced lugs.
Similar to caliber MT 5621, which was launched this time last year in the North Flag, the MT 5601, is automatic, beats at 4Hz, has 28 jewels, and boasts a 70-hour power reserve. Moreover, it uses a silicon balance spring and has a variable inertia balance wheel, with a traversing balance bridge which makes the regulator assortment more robust. The difference, between this movement and what powers the North Flag, is that the Black Bay movement lacks a power reserve indicator, date, and is slightly bigger (to better complment the new 43 mm Bronze case).