Roof Parts: Includes all the parts you need for the roof already assembled and ready to install. The Dome is already fixed to the Breather Frame, the Tabs are already installed and all of this is already fixed to the flashing. There are different flashing to suit different roof types such as Tile, Slate, Metaldek, Custom Orb (CGI) etc Attic Parts: The parts that link the Roof & Ceiling. A choice of either Flexi-tube or Rigid98 Tube. Flexi-tube is more economical, easier to install and has very good efficiency. Rigid98 Tube has outstanding efficiency but takes longer to install and is more expensive. Flexi-tube is only recommended for lengths of 3m or less. Ceiling Parts: This includes all the parts you need for the ceiling. A ceiling frame/trim which is screwed to the ceiling, a ring for locking the flexi-tube into position and a double glazed diffuser system that magnetically fits to the ceiling frame. All the fixings you require for installing these parts are also included.