14 in. Aura Gravity Vent with 4 in. Collar and Curb Mount Flange
24 in. Aura Gravity Vent with 4 in. Collar and Curb Mount Flange
C4-73 Best Price Heavy Duty Industrial Reverse Air Reverse Air Blower Centrifugal Ventilation Fan - China Backward Centrifugal Fan, Backward Centrifugal Fan Catalogue | Made-in-China.com