Making an ultra thin movement is much more difficult than you can think.
There is a very tough compromise to find the perfect ratio between the thinness, and the reliability, the solidity of the parts composing the movement.
LeCoultre, then Jaeger-Lecoultre developped a true speciality and mastery in ultra thin movements, since 1907, which were manual but also automatic.
Here, you will find a list of these movements, which are true piece of art, and, sometimes, offered more than simply the Hour and the Minutes, but some prestigious complications, like a Minute Repeater.
I/ Manual movements:
Cal 145 from 1907.... 1, 38 mm high!
Cal 18 SMV, circa 1920, Minute Repeater, AND Ultra Thin. Even if I don't have the height of this movement, I have seen in the real life, and I can vouch for its thinness:
Cal 803, 1953.... 1, 64 mm high.
Cal 818, 1959: 2, 94 mm high.
Cal 849, 1994: 1, 85 mm high.
II/ Automatic movements:
Cal 920, from 1967: 2, 45 mm high, made by Jaeger-Lecoultre, used by Audemars Piguet and Vacheron Constantin, for example.
Cal 896, from 2008: 3, 98 mm high, but does it have still to be considered as Ultra Thin?
Who else is able to offer such a diversity?
Best,
Nicolas