Cal. MT5641 is an in-house big date movement from Tudor, introduced in 2018.

Tudor traditionally used movements from major manufacturers, chiefly ETA in modern times, as a differentiator from parent company Rolex. Beginning in 2015, the company began producing a line of “Manufacture Tudor” movements for certain models. These are based on Rolex technology, and include that company's silicon hairspring technology, full balance bridge and free-sprung Microstella balance wheel.

Cal. MT5641 features a big date window at 12 00 and small seconds at 6 00. Cal MT5641 is finished in a simple “industrial” motif rather than with elaborate anglage or finishing.

This movement features modern technology, including bi-directional winding, hacking seconds, instantaneous date change with crown-based quickset, and a variable-inertia balance with micro-adjustment by screw and silicon balance spring.

Cal. MT5641 was used in the following models:

• Tudor Glamour Double Date 57100 (2018-present)