Powering the Portuguese Chronograph Classicis an IWC-manufactured 89361 calibre, developed specifically to record time spans of up to 12 hours on a subdial. The result is as bold and easy to read as a clock face. The sapphire-glass back reveals the 89361 calibre and the rotor, resplendent in Geneva stripes. The Portuguese Chronograph Classic is available in 18-carat rose gold or stainless steel, both with silver-plated or slate-coloured dial.