AP Royal Oak Ladies - is it a ETA movement

[sinasera]

I am going to get one for my better half and I wonder what movement is this watch?

Audemars Piguet Lady Royal Oak Automatic Watch #77321ST.ZZ.1230ST.01

[mn85]

Certainly not an ETA movement. If I recall correctly, the AP cal. 2140 is based on a JLC movement. I'm sure she'll love it!

[emmanuelgoldstein]

Certainly not an ETA movement. If I recall correctly, the AP cal. 2140 is based on a JLC movement. I'm sure she'll love it!

You are correct. AP Caliber 2140, 28,880 vph, 31 Jewels, power reserve 40 hours.

[ciaca]

The AP2140 is based on JLC960 ebauche, related to the widely used and well known jlc889, a little bit smaller in diameter but thicker than the 889, with more construction pieces (226 against the 202 pieces of the 889). The most noticeably difference is the barrel and the automatic winding bridge, the barrel is a "floating type" (without upper arbor pivot supported by the winding bridge).
The small size of the movement puts it in a different class than the 889's one, the class of the small calibers in which Frederic Piguet 961 dominated. And the 960, compared to FP, shows a better performance in the winding system thanks to the Peripheral massive 21k gold weight.
The finishing of the movement is quite a good industrial one with no refinement of hand done work, nothing to die for as usual in the JLC ebauche gamut used by AP (exception done for some calibers, like the lovely 920 used in the jumbo family).

Regards