Automatic movement based on LaJoux-Perret 6901. Available both with and without date - the former being reference BWC/01-10.
Automatic with 25 jewels, Glucydur balance, Nivarox CT balance spring and Nivaflex 1 mainspring. Highly efficient double reverser bi-directional winding mechanism to achieve 28,800bph and 50+ hour power reserve.
Pictured as used in the Wright Flyer.