... according to impeller diametar,could divided to NO.2.8, 3.15, 3.55, 4, 4.5, 5, 5.6, 6 ... .3, 7.1, 8, 9, 10, 11.2 and so ... and other hotel .office block,movie theater .so on Explosion proof Axial Flow Fan Type BT35-11Application1,Designed forExplosive atmosphere Zone ... it can meet the required wind rated and wind pressure.3,Impeller structure is adjustable, it is can be adjusted flexibly ...