FRP cowl and base with axial flow fan impeller; high air flow fan and efficiency; installable on roofs or walls to suit different building structures.Indoor ventilation for petroleum, chemical, textile, metallurgical, and machinery workshops, offices, laboratories, and warehouses. Medium temperature<25℃, relative humidity <90%, dust content (solids & impurities) <100 mg/m3.Corrosion-resistant version (FWT35) available for corrosive gashandling, with identical performance parameters; reverse-flow version available upon special request.