... chemical, medicine, tea, vegetable storage, and supermarketDJF-C series Cone exhaust fansReasonable cone designing, low noise, big air ... pvc shutter or aluminum shutter,antioxidant, light weight, no distortion,open and close sweetly,prevent backflow of airHigh- ... , high strength, toughness good 6 pcs stainless steel blades, no distortion, no breaking, aesthetic durabilitytwo types fan house:slant wall ...