What's the story on these movements? Are they ETA derivatives or built from the ground up by the manufacture?
Totally in house, launched in 1994 exactly because Zenith wanted to stop having to use ETA movements in its three handed watches. It won some awards at its debut, I believe. Its a very good piece of work, but remains relatively unklnown in the shadow of its famous older brother, El Primero. You'll note that in versions without central seconds, the small seconds hand is at the 9 o'clock position. Rumor has it that the Elite was created as a new platform for a whole range of movements, including chronographs, hence that location. In the end, though, Zenith decided El Primero was too valuable a property to mothball.
All true, plus as Roessler points out, the design made the movement very versatile, appearing with central seconds, and sub seconds variously at 3, 6 or 9 o'clock depending on other features such as reserves-de-marche, double time zones and 24 hour dials. Plus, of course, the movement is easily capable of earning chronometer certification and boasts a number of chronometer models In both hand-wound and automatic versions. C'est marveilleuse!
I have one of its Elite 670 watch and the movement is so thin and beautiful. Absolutely one of my all time favorite automatic movement. 100% in house!