IWC, LIMITED EDITION PLATINUM PORTUGUESE PERPETUAL CALENDAR, REF. 5023-05, NB. 012/250

The IWC Portuguese Perpetual Calendar 5023 was introduced in 2010, pairing IWC's self-winding 7-day movement with Kurt Klaus' ingenious perpetual calendar module. It featured a case of 44.2mm with sapphire glasses both front and back. One of its signature elements was the 'Single Moon' moon phase display, allowing its owner to read the moon phase in its hemisphere.

This reference, the IW5023-05 features a platinum case with a silver colored dial. It was introduced in 2011 and is limited to 250 pieces.