Seiko Epson PX82A

PX82A is an Epson automatic-power-generating quartz movement, marketed as Hybrid Automatic. Body motion generates electrical energy stored in a secondary lithium-metal battery; it is not a mainspring-powered automatic movement. It has central hours, minutes and seconds, a quick-setting date and a power-storage indication activated by the button at 2 o’clock. Its outside diameter is 27.60 mm, casing diameter 27.00 mm and height 4.89 mm including the battery. Expected running time after full charge is approximately six months. The oscillator operates at 32,768 Hz with rated accuracy of ±20 seconds per month.