Audemars Piguet Perpetual Calendar 5548 Yellow GoldRare and important to AP The reference 5548 is regarded as the watch that saved Audemars Piguet, during the so called Quartz Crisis of the early 1970s. The watch is rare as it is believed that only around 2000 pieces were made. The watch is driven by the JLC Calibre 2120 with a Depraz perpetual calendar module added. Even with the module, the movement is only 3. 95mm thick! The movement is housed in a slim and elegant 36mm yellow gold case, that has a