... . 4.Energy saving. Circular ultrathin Exhaust fan BPT16-13CModel:BPT16-13C,70CFM,118m3/h, 0.8sones, 38db,4"Duct,Power:28W 1.50CFM ... power consumption,low temperature-rising,environmental,over-heat protection device in design,achieve to free maintenance,long life and high efficiency ... ,CFM:70CFM(118m3/h),suitable for 65-85Sq.Ft.4 Circular ultrathin Exhaust fan BPT16-13C