Divers offer a better waterproofness than traditional watches. They are equipped with a graduated rotative bezel in order to calculate diving time and they also feature a better luminescence.
Watches featuring a « big date » display an oversized window and have two independent date discs.
The date is a small window on the dial which indicates the day of the month (between 1 and 31).
The central second is the central hand of the dial which divides the minute into 60 units.