The PAM355 has a hand-wound mechanical (huh, hang on...) OP XXIV movement that offers a lot of functions; hours, minutes, seconds, date, a second time zone and an alarm. Not bad to have all of that in a 42mm case. It is actually a new version of the PAM98 which dates back to 2001. That watch had an automatic Girard-Perregaux caliber. The PAM355 however has Panerai's OPXXIV movement.