Patek Philippe: Case with invisible hinge

The rose-gold case of the Ref. 5227R is an eye-catcher not only because of its svelte silhouette but also because of the dust cover that protects the sapphire-crystal case back. It is attached with a hinge that is invisible from the outside, a manifestation of considerable savoir-faire. Dwelling on this example, the video shows just how much artisanal prowess and experience are needed to complete such a case, integrate the tiny hinge, and attach and adjust the dust cover.

5227
DATE. SWEEP SECONDS.
SELF-WINDING MECHANICAL MOVEMENT
CALIBER 324 S C
Dial: ivory lacquered (yellow, white or rose gold) or black lacquered (white gold), gold applied hour markers. Case: yellow, white or rose gold. Sapphire-crystal case back protected by an invisibly hinged dust cover. Water resistant to 30 m. Diameter: 39 mm. Height: 9.24 mm.

http://www.patek.com/en/mens-watches/...