... quality size :1380*1380*400 Product Name: Industrial Exhaust Fan (Negative Pressure Fan)Suitable Occasion: workshop, barn, greenhouse, auditorium, textile plant, shoemaking ... , odor and bad ventilation are totally solved.Product technical specification: Rotary Air Noise Power Rated Weight OutsideModel speed flow dB(A ... 28000 55 0.55 380 55 1065×1065×950 horn-type exhaust fan