The IWC Portugieser Tourbillon Day & Night (ref. IW545901) brings a dramatic new tone to the classic Portugieser line with its pairing of Armour Gold and a rich black sunray dial. Limited in production and visually commanding, the model centres on a flying tourbillon at 6 o’clock and introduces a novel day/night indicator at 9 o’clock—each complication housed within an elegant 42mm case.

Crafted from IWC’s proprietary Armour Gold, the case delivers superior hardness and resistance to wear while preserving the warmth of traditional red gold. The black dial is accented with gold Arabic numerals, feuille hands, and a guilloché inner dial that elevates contrast and legibility. Powering the display is the hand-wound calibre 81925, visible through the sapphire caseback, offering 84 hours of power reserve and finished to exacting standards. The watch is water-resistant to 50m and comes on a black alligator strap with gold folding clasp.

As one of the most complex and visually striking executions in the modern Portugieser family, the IW545901 underscores IWC’s ongoing push into high-complication territory—melding technical refinement with bold, contemporary design.