IWC IWC - IW3910-27 Portofino Chronograph Stainless Steel / Silver

Portofino Chronograph Stainless Steel / Silver

REF. IW3910-27

2/10

Widely produced

Case

MaterialStainless Steel

Diameter42 mm

ShapeRound

CrystalSapphire

Case backClosed

Water resistance30 m

Dial

ColourSilver

IndexesStick / Dot Hands: Feuille

HandsFeuille

Movement

Caliber75320

Typeautomatic

Reserve44 h

Explore caliber→

In Context

At 42 mm it is sized to the current mainstream: 40 mm is the median across every watch measured in this catalogue. At 13.6 mm it is a tall case, and it will catch on a cuff. The case back is closed, so the movement stays out of sight, and the sapphire crystal will resist everything short of deliberate abuse. Rated to 30 m, it is protected against rain and splashes and nothing beyond that.

The movement winds itself from the motion of your wrist. 44 hours of reserve carries it overnight, but not through a weekend in a drawer. At 28,800 vph the seconds hand advances 8 times a second.

IW3910-27 is one of 22 executions of the IW3910 base reference. Underneath they are the same watch; what separates this one is a silver dial and a stainless steel case. Introduced in 2019. Beyond the time it carries a chronograph.

The IW3910 family

IW3910-27 is one of 22 variants sharing the IW3910 base reference — same watch underneath, different dial, bezel, or bracelet execution. Browse the others:

IWC

Silver · Stainless Steel

IW3910-01 · 42 mm

IWC

Black · Stainless Steel

IW3910-02 · 42 mm

IWC

Silver · Stainless Steel

IW3910-05 · 42 mm

IWC

Black · Stainless Steel

IW3910-06 · 42 mm

IWC

Silver · Stainless Steel

IW3910-07 · 42 mm

IWC

Black · Stainless Steel

IW3910-08 · 42 mm

IWC

Blue · Stainless Steel

IW3910-19 · 42 mm

IWC

Blue · Stainless Steel

IW3910-23 · 42 mm

+ 13 more variants in this family.

Inside: Caliber 75320

Explore this caliber →

The Portofino Chronograph's automatic chronograph, built on a Sellita SW500 — the clone IWC turned to once ETA stopped supplying Valjoux 7750 ébauches outside the Swatch Group. It is the direct successor to the 79320, which used the 7750 itself, and the layout carries over unchanged: counters at six, nine and twelve with a day-date aperture at three. IWC regulates and finishes the base before fitting it.

14 other watches in the library run the IWC 75320.