What time is it? Watches and horology

It’s unconventional and a bit harder to make work (because you have less torque going into the winding mechanism). Mostly it’s because if you want to do a thin (sub-4mm) automatic GMT with day/night and a power reserve you have to design and build it yourself. No off the shelf movement to base it on.

That’s why the price is impressive. Like their tourbillon - I think the preorder price for those was “only” about 7k. No one else doing that kind of stuff at the price.