百達翡麗，罕有，18k金長方形石英腕錶，配中心秒針及日曆顯示、型號3603，1974年製

Reference 3603 such as the present example was in production from 1973 until 1982 and is together with references 3587 and 3597 amongst the largest rectangular wristwatches ever made by Patek Philippe. Available in either yellow or white gold with Ateliers Réunis cases, the dials were made by Stern Frères from a massive 18k gold plate and were available in either blue, gilt, browned or silvered finishes.

The Beta-21 calibre was developed by a consortium of watch companies, including Patek Philippe, at the Swiss Electronic Research centre or CEH (Centre Electronique Horloger) in Neuchâtel. It was the first quartz movement for wristwatches with analogue display.