PWM 500 ~ 2000 R.P.M High Air Pressure Fan Blade: 54.71 CFM High Air Flow Fan Blade: 62.23 CFM Reverse Fan Blade: 58.17 CFM Hydraulic High Air Pressure Fan Blade: 26.5 dB-A High Air Flow Fan Blade: 28.3 dB-A Reverse Fan Blade: 29.8 dB-A