The latest member of the Portofino watch family welcomes a new and technically sophisticated model to its ranks named Portofino Hand-Wound Monopusher (ref. IW515103/IW515104). This newcomer is the very first timepiece with an ingenious single push-button chronograph function which measures time up to 60 minutes.
The chronograph push-button is integrated in the crown and at glance it stays invisible. Repeatedly pressing the single, multifunctional push-button starts, stops and resets the chronograph. When the button is pushed for the third time, all chrono displays return to zero.
The beating heart of the Portofino Hand-Wound Monopusher is a newly developed caliber 59360 movement which, when fully charged, will run precisely 192 hours (eight whole days) before automatically stopping.
The hand-wound movement oscillates at the rapid frequency of 28,800 alternations per hour (4 Hz) and it is built on 36 jewels. The impeccable mechanism is a worthy addition to IWC’s in-house movements and the Portofino range.
The amount of energy that remains is showed on the power reserve display which is located between 8 and 9 o’clock position on the dial. The subsidiary dial at the 12 o’clock position displays the chronograph minutes, whilst the chrono seconds can be read off on the central hand. Its dial also comprises a small seconds counter which is located at the 6 o’clock position and the date display which is shown in an aperture located at the 3 o’clock position.
From the rear, the view through the sapphire display back is equally interesting. The sapphire-glass back displays an IWC-manufactured movement encrusted with Geneva stripes together with the chronograph mechanism.
The new Portofino Hand-Wound Monopusher is available in two variants each of them representing a stylish expression of understated luxury. The first one is the model with the referent number IW515103 that sports 18-karat white gold case, a slate-colored dial and Santoni strap made of gray alligator leather, fitted with a white gold pin buckle. The second version of the Hand-Wound Monopusher with the reference IW515104 matches 18-karat red gold, silver-plated dial and Santoni strap made of brown alligator leather, ending with a red gold pin buckle.
The watch case measures 45mm in diameter and 13mm in thickness and it is protected on both sides with sapphire crystals with anti-reflective coating. It is proven that the watch is constructed to be water resistant up to 30 meters (about 100 feet).