Only a few complications in Haute Horlogerie are as fascinating as the tourbillon. The "whirlwind" involves the balance wheel rotating around its axis in a cage. This not only provides a visual spectacle on the dial. The constant rotation reduces the influence of gravity on the oscillation system and increases the accuracy of the timepiece. The Portugieser Tourbillon Rétrograde Chronograph features a flying hacking minute tourbillon at "6 o'clock". Additionally, the model is equipped with a retrograde date display and a chronograph with flyback function. Limited to 50 pieces, the case of this watch is made of platinum. The silver-plated dial and the rhodium-plated hands and appliqués harmonise wonderfully with the rare precious metal. The self-winding IWC-manufactured 89900 calibre boasts a power reserve of 68 hours. The pallet lever and escape wheel are treated using Diamond Shell® technology, which reduces friction and improves the flow of energy in the movement.