Marine Chronometer, Annual Calendar function automatically adjusting for leap years until March, Automatic movement with Calibre UN-113 mechanism operating at 28800 vph and providing approximately 60 hours of power reserve, Blue dial featuring silver-tone spade-shaped hands and Roman numeral hour markers, Minute markers on the outer bezel. Includes sub-dials for month display (at 3 o'clock) showing current month via apertures, date at 6 o'clock, power reserve indicator. Silver-tone stainless steel case with fixed bezel and matching bracelet, Sapphire crystal glass is scratch resistant, Screw down winding crown allows adjusting time or setting the date manually if needed, Transparent case back enables viewing of the automatic movement inside. Round shaped watch case measuring 43 mm in diameter and having a thickness of 13.85 mm. Equipped with folding clasp closure system for secure wearing underwater up to 100 meters (approximately 330 feet) water resistance depth, Analog dial type displaying hour markers, hands and sweep second hand. Functions include: hours, minutes, seconds, date display at the 6 o'clock position, annual calendar complication automatically advancing the date until March of leap years, power reserve indicator showing remaining energy.