A diffuser is a commonly used air supply outlet in air conditioning systems, with uniform flow characteristics and a simple and beautiful appearance. It can be made into a square or rectangular shape according to usage requirements and can meet any ceiling decoration requirements. The inner core of the diffuser can be detached from the outer frame for easy installation and cleaning. A vent control valve can be installed at the back to control and adjust the air volume. Suitable for broadcasting studios, hospitals, theaters, classrooms, music halls, libraries, amusement halls, theater lounges, general offices, shops, hotels, restaurants, and sports centers. In order to avoid noise interference and discomfort in various environments, in addition to determining the neck wind speed according to the performance table, it is also necessary to consider the installation height and installation location.