Exhaust Fan with Drive Package Assembled Unassembled Blade Diameter 20 in Blade Material Steel Drive Type Belt Drive Exhaust Airflow @ 0.000 in SP 5 550 cfm For Cut-Out Height 22 1/2 in For Cut-Out Width 22 1/2 in Frame Finish Zinc Plated Frame Material Steel Guard Type None Includes Drive Package Includes Dehumidistat No Maximum Airflow 5 550 cfm Maximum Noise Level 17.9 sones