Finally, each case is hand-polished for a long time to create the effect of mirror light. Patek Philippe launched the No.5940 watch, which turned a new page in the perpetual calendar timepiece and restored the cushion-shaped case, making the watch as attractive as the 1920 and 1930 art nouveau works exhibited in Patek Philippe Timepieces Museum. The watch is made of matte black crocodile leather strap with square texture, hand-stitched, and matched with 18K gold buckle.