horn-cone fans 1.air flow 49530m3/h . 2.cone fan can ... cone fans1. Reasonable cone designing, low noise, big air flow, strong ventilation, low operating cost;2. Imported bearing ... , high-strength, low noise, durable3. Using air downstream principle, pvc shutter or aluminum shutter, antioxidant, ... , open and close sweetly, prevent backflow of air,4. High-strength more high-gluten strength aluminum ...