The IWC Portuguese Chronograph Ref. IW371402 is one of the most iconic luxury dress chronographs of the modern era. Known for its flawless symmetry and vintage-inspired marine chronometer roots, this specific variant pairs a solid 18k rose gold case with a clean silver-plated dial. It was originally introduced in the late 1990s/early 2000s and was officially discontinued around 2010 when it was succeeded by the Ref. IW371480 (which shifted from 4N rose gold to 5N red gold).

• Case Dimensions: 40.9mm diameter (commonly categorized as 41mm), 12.3mm to 12.6mm thickness, and a 47mm lug-to-lug profile. The ultra-thin bezel makes the dial footprint look large and legible on the wrist. 

• Case Material: Solid 18k rose gold (4N alloy) with a solid 4-screw engraved gold caseback. 

• Dial & Hands: Crisp silver-plated dial with applied rose gold Arabic numeral markers, dot minute markers, and elegant feuille (leaf-shaped) hands. 

• Layout: Vertical bicompax chronograph symmetry, featuring a 30-minute counter at 12 o'clock and a small running seconds subdial at 6 o'clock. It features no date display. 

• Μηχανισμός: IWC Calibre 79350 automatic movement. This highly reliable caliber is heavily modified by IWC from the proven Valjoux 7750 base. It features 31 jewels, beats at 28,800 vph (4Hz), and holds a 44-hour power reserve. 

• Crystal: Scratch-resistant convex sapphire crystal with anti-reflective coating on both sides.

• Strap & Buckle: Typically paired with a premium brown or black alligator leather strap and an original 18k rose gold tang/pin buckle.

• Water Resistance: 30 meters (3 ATM), providing basic splash protection but not intended for swimming or showering.