This is the Audemars Piguet caliber 2601quartz movement. This caliber can be found in ladies size Royal Oak models.
Some of the topics covered in this caliber listing:
According to Audemars Piguet, the accuracy of the quartz caliber 2601 is +/-2 minutes per year.
Battery Power Reserve
A fresh battery should last for a minimum of 36 months. The battery cell is a number 321 with a diameter of 6.80mm and thickness of 1.65mm. The voltage rating is 1.55 V.
Time Setting Instructions
Setting the AP caliber 2601 depends on the model. There may be a pusher in the center of the crown, or a pusher on the back of the case. To set the time, use the pusher:
Quick press to advance the minute hand forward by one minute.
Press for 2-4 seconds to advance the hand forward by one hour (useful for changing time zones).
Long press to move the hands forward continuously.
In Audemar Piguet’s Own words:
“Quartz is a dominant element at Audemars Piguet. Used for the first time in the 70s, it completely revolutionised the notions of horological precision. Despite its superior performance, quartz technology does not enjoy the same prestige as mechanical watchmaking. However, in deciding to optimize the performance of its electronic movements, Audemars Piguet revives the glory of this advanced technology which enables the creation of ultrasophisticated instruments for professionals.”
AP Explains the technology:
“From the technical point of view, quartz movement are based on a regulator (the time-measuring element) consisting of a quartz crystal through which an electric current is passed. This “resonator” vibrates at an extremely high frequency (32’768 Hz), dividing the time into equal intervals. In an analogue display quartz watch, an integrated circuit records the electric signals transmitted by the quartz oscillator and divides their frequency into pulses equivalent to one, five or ten seconds.” -AP Quartz Movement Instructions for Use Manual