IWC Portugieser Annual Calendar Automatic Mens Watch IW503501. Stainless steel case with a black alligator leather strap. Fixed stainless steel bezel. Silver dial with silver-tone hands and Arabic numeral and index hour markers. Minute markers around the outer rim. IWC Calibre 52850 automatic movement with about 168 hours of power reserve. Scratch resistant sapphire crystal. Pull / push crown. Skeleton case back. Case size: 44.2 mm. Case thickness: 15.3 mm. Round case shape. Deployment clasp. Water resistant at 30 meters / 100 feet. Functions: date, day, month, hour, minute, second.