1. adopt the system which open and close automatically when the fan works
2,centrifugal shutter system and other fitting of shutter made of Nylon mhig quality engineering plastic s , 100% raw materials high strength , and 0long service life .
3, The inner steel fitting install in the flange , increasing the security , avoid the stretcihng change when Nylon system operate s.
4. adopt the injection molded stainless steel blade , no broken , no distortion , , easthetic and durable .
5. The efficient and energy saving motor passed the national CCC certification , also protection class :IP55 , insualtion : F grade .