【Material】: Aerodynamic design, strong wind pressure and high efficiency. The exterior is made of high-quality metal protective mesh. The durable hollow design on the back can achieve effective heat dissipation and consume air volume throughout the day without causing internal ultra-core electromechanical load. The all-copper mechanism, ball bearings are maintenance-free and contain enough grease to last a lifetime.【Humanized Design】: There is an automatic valve at the end of the exhaust fan that can automatically open and close with the fan to prevent mosquitoes from entering when not in use. Single-sided ventilation eliminates outdoor high-temperature gases and polluted air and prevents high-temperature air from entering the room.【Easy to Assembl.