Powerful Ventilation: This Roof Mounted Fan with a speed of 2500 RPM can create 897 CFM air flow, efficiently circulating fresh air to achieve optimal ventilation. High Quality Material: The Roof Vent Fan Metal shell for precision mold stamping and spray processing, which is corrosion-resistant and exquisite in appearance. Low Noise: Using single-phase external rotor motor, the whole machine has low noise. Reliable Guarantee: ETL Certificate. The quality of roof fan has been strictly checked and can be used with confidence. Widely Used in hotels,auditoriums, conference rooms, supermarkets, stations, airports, greenhouses air supply and exhaust in public places such as plants. This Roof Extractor Fan with a speed of 2500 RPM can create 897 CFM air flow, efficiently circulating fresh air to achieve optimal ventilation.