White shell gold shell ZF IWC Portuguese annual calendar watch boutique IW503501 model! Upgrade details 1. Diameter 44 mm, consistent with the original size! 2 Exclusively customized version of the 52850 movement with synchronized functions with the original (month/calendar and week display, truly adjustable, the only full-function version on the market) 3 Using a high-permeability coated pot lid sapphire mirror, the visual effect is extraordinary! 4. The brushed craftsmanship of the case is comparable to that of the genuine product, and it is perfectly polished. As the backbone between perpetual calendar and ordinary calendar watches, this is bound to become a new star of attention for replicas! ,