In 2010, IWC released the Portugieser Perpetual Calendar 5023, which combined their self-winding 7-day movement with Kurt Klaus' brilliant perpetual calendar module. This module, originally used in the 1985 Da Vinci, was adapted to fit the larger 7-day movement. The watch boasts a 42.2mm case with sapphire glass on both the front and back. One unique feature is the 'Single Moon' display, making it easy to read the moonphase in its hemisphere. The IW5023-02 model, introduced in 2010, has a luxurious red gold case and a silver dial.