IWC Portuguese Perpetual Calendar Blue Dial 18kt White Gold Black Leather Mens Watch IW503203. 18kt white gold case with a black leather strap. Fixed bezel. Blue dial with silver-toned hands and Arabic hour markers. Minute markers around the outer rim. Automatic movement. Calibre 51614 engine. Scratch resistant sapphire crystal. Case diameter: 44.2 mm. Round case shape. 18kt white gold tang clasp. Water resistant at 30 meters / 100 feet. Functions: year, month, date, day, hour, minute, second, moonphase.