天窓 is Skylight, which means not Window.
Skylight is usually curb required on the roof for waterproofing, then on curb Skylight is set up.
Curb itself is usually Wood Cant and cladded by Metal Flashing (Aluminum or Galvanized Metal).
Type Skylight at web site, then you will get some manufactures.
If still you have any question, please write down here.