Girard-Perregaux Richeville Chronograph "Monte-Carlo 1954"
with tonneau shaped case
© Girard-Perregaux

Case shape

Tonneau (French) for ton or barrel barrel-shaped watch housing, today a very popular kind of case design.

A further development of the tonneau shape, with a higher complexity of curvature, can be found at the Cintrée Curvex case, which is used by Franck Muller for many of his watches.