The case design remains basically unchanged. 18k rose gold is used to form a rough outline, and the space in the middle is filled with sapphires, allowing the owner to see the movement inside at a glance. The case diameter of Jacob & Co. Astronomia Solar is 44.5 mm, which is slightly smaller than other Astronomia watches. The thickness of the case is 21 mm, and yes, this is not a typographical error. That's because the case itself must be large to accommodate the wonderful 3D movement, and it has a domed sapphire crystal. So, Astronomia Solar, like other Astronomia watches, is really thick. Don't expect it to slip under the shirt sleeve, don't worry, everyone will notice it on your wrist-of course, you already know it.