DJF series Centrifugal Shutter System Exhaust Fan (Auto push-pull type exhaust fan. ) Centrifugal shutter system:1)Adopt the this system which open and close automatically when the fan works.2)Centrifugal shutter system and other fitting of shutter made of Nylon, high quality , 100% raw material, high strength, and long service life. 3)The inner steel fitting install in the flange, increasing the security, avoid the stretching change when Nylon system operates. Blade:4)Adopt the injection molded Stainless steel blade, no broken, no distortion, aesthetic and durable.5)Balance running machinery checked the entire fan blades balance; ensure operating steady, low noise, long service life.6)Adopt the handle as new inset design from our engineer, easy for carry, transport and installation. Also has no affect on the appearance. 7) It made of high quantity aluminum-magnesium alloy, light weight, high strength. 8) We could supply V-belt as the type A or type B, upon the varieties demand of different customers. 9)The high efficient and energy-saving motor passed the national CCC certification. Also protection class: IP55, insulation class: F grade. Centrifugal shutter exhaust fan Model Specification Balde Diameter mm Blade speed rpm Motor Speed rpm Air flow m³/h Pressure Pa Noise Decibels Import Power W Rated Voltage V High mm Wideth mm Thick mm DJF-1000 900 438 1400 21000 57 ≤65 550 380 1000 1000 450 DJF-1380 1250 437 1400 44000 57 ≤65 1100 380 1380 1380 450