Alpina Horloge - Kaliber 490

Alpina 
Roestvrij staal  
1938  
Mechanisch handopwind 
15 Jewels  
Uurwerk kal. 490  
​Swiss made  
± 38/29.6 x 23 mm

This rectangular Art Deco Alpina houses the legendary Caliber 490, the movement for which Alpina introduced the designation "6". To celebrate its 140th anniversary in 2023, Alpina reintroduced the Caliber 490. According to the brand, it is not a revamped edition or or inspired by, but an exact recreation of the original 1938 movement, the very same caliber found inside this Art Deco Alpina. That fact alone says a great deal about the unparalleled quality and enduring reputation of this movement. 
The movement is not only a robust construction but it has also received a perfect refined finish, every single component has beveled edges, and the ratchet has been given an elegant sunburst finish, demonstrating the level of craftsmanship that went into its production. Developed by Union Horlogère, Alpina's original manufacturing entity, the Caliber 490 was introduced in 1935 and officially registered in 1938, when it was granted a Swiss patent. With a power reserve of approximately 42 hours, the movement was exceptionally advanced for its era. Even by today's standards, it remains an impressive and highly capable caliber.
Why this movement received the number 6? It refers to six technical innovations/plus points; 1. Water-Resistant 2. Powered by Alpina caliber 490 3. Anti-Vibrations 4.  Shock-Resistant 5. Anti-Magnetic 6. Durable, stainless-steel case.
The movement is securely protected by the snug fitting dust cover. Which is held in place by tiny retaining tabs at either ends , which lock neatly into place making a little click sound when perfectly positioned. 
Protection doesn't end there. Alpina also patented the ingenious crown construction, which played an important role in the early development of water-resistant wristwatches and paved the way for future waterproof case designs throughout the watch industry. 
As shown in the photo, the crown is recessed into the first layer of the case, a subtle detail that I always appreciate.
The dial is original and has some signs of age, though the Alpina brand name looks remarkably crisp, almost as though it has just been freshly printed. For the most part the dial has a finely brushed silver surface, contrasted by the smooth finish of the sub-second circle and the index scale which catch the light at every chance. Completing the dial are blued steel hands with their original luminous filling.
Fitted with a one-piece dark blue NATO strap, the watch strikes a wonderful balance between ruggedness and elegance.
Overall, this is an outstanding Art Deco Alpina fitted with one of the finest manually wound calibers of its period, a movement whose engineering, finishing, and historical significance continue to justify its legendary status.