Portofino reference IW510102, a stainless steel hand-wound wristwatch with 8 days power reserve, Circa 2021

Over the past 30 years, the IWC Portofino watch family has welcomed a stream of new timepieces and complications.

The large, precise, hand-wound movements in the 59000-caliber family have an 8-day power reserve, but could theoretically run for 9 days. The extra day in reserve ensures that the movement maintains as constant a driving torque as possible and continues to run precisely. The movement is stopped mechanically before the reduced torque can cause it to start running inaccurately. This also means that the owner can safely wind the watch once a week. The indexless balance has a frequency of 4 hertz (28,800 beats per hour) and, together with the Breguet spring bent into shape in accordance with age-old watchmaking tradition, helps to make the watch exceptionally accurate.

This watch features 8 days power reserve and date display, small hacking seconds. Arched-edge sapphire glass, antireflective coating on both sides. Indexless balance with four golden weight screws on the balance rim. This is a manual-winding watch 59210 caliber movement with 192 hours of power reserve. Dark brown alligator leather strap by Santoni. Circa 2021 with original box and paper.