Lay In Diffuser is made of Aluminum extrusions which adapts Plastic Clamshell Teflon technology. It provides multi-angle even supply air and large diffusion range. The supply air angle may be between 35°- 38° and the discharge surfaces can be in 4 ways, 3 ways or 2 ways (which is optional.) It is used in the return air system and the internal frame is removable which is much easier to be installed and cleared. It is mainly applied to department stores, theaters, restaurants, living rooms and inner rooms.