1) Made of double inlet centrifugal fans with forward curved blades; 2) Wide usage 3) High efficiency, low noise. Material: Galvanized sheet, or as customers' request.Size: 7'X7'--18'X18'Motor: as customers' request'Characteristics:1) Made of double inlet centrifugal fans with forward curved blades 2) High efficiency, low noise, large volume flow and compact construction 3) With metal scroll; ...