Audemars Piguet. A protracted-time favored with the elite, AP is really an icon of watches equally aged and new. They may be unafraid to test new things, Which explains why they have lots of unorthodox items of their selection.Helium Escape Valve (HEV): At first co-developed by Rolex and Doxa, this can be a small, spring-loaded a single-way valve t