IWC Portugieser Chronograph Steel — Silver-Plated Dial | Ref. IW371605

Calibre 69355 occupies a place of genuine distinction within IWC's movement portfolio: a self-winding chronograph architecture built around a column wheel — the traditional, mechanically superior switching mechanism — that governs the complication's start, stop, and reset functions with the kind of tactile precision that pushbutton chronographs with cam-and-lever systems rarely achieve. In the Portugieser Chronograph IW371605, this calibre finds an environment worthy of its engineering: a 41.0 mm stainless steel case whose see-through sapphire caseback was designed specifically to put the movement on display.

The silver-plated dial carries the hallmarks of the Portugieser vocabulary — the railroad-track minute ring, the outward-radiating chapter ring, the hierarchically scaled subsidiary dials for small seconds and elapsed chronograph minutes. At 13.0 mm in thickness, the case is noticeably slimmer than many column-wheel chronograph references, a consequence of the calibre's efficient architecture. Approximately 46 hours of power reserve is delivered from the automatic winding rotor, whose momentum is transmitted to the mainspring through IWC's proven winding system. Convex sapphire crystal with bilateral anti-reflective coating maintains dial clarity without introducing unwanted reflections.

The blue alligator leather strap introduces a considered chromatic counterpoint to the silver dial and steel case — a combination that reads as understated during business hours and accomplished during evening wear. The IW371605 occupies the sweet spot in the Portugieser chronograph range: complete in specification, refined in execution, and positioned to remain a reference-caliber choice for the informed buyer.