exhaust fan high quality best service exhaust fan1. Fan Box Material: 1mm thickness galvanized steel panel. 2. Fan Blade Material: 1.5mm thickness galvanized steel panel. 3. Shutter Material: 0.5mm thinckness galvanized steel panel. Automaticlly (Air flow pressure) close design. 4. Motor: 380V/50HZ, 3Phase, 1Speed, Home-made motor. poultry exhaust fan