Exhaust/Supply Fan Assembled Unassembled Blade Diameter 48 in Blade Material Aluminum Drive Type Belt Drive Exhaust Airflow @ 0.000 in SP 20 913 cfm For Cut-Out Height 50 1/2 in For Cut-Out Width 50 1/2 in Frame Finish Zinc Plated Frame Material Steel Guard Type None Includes Drive Package Includes Dehumidistat No Maximum Airflow 20 913 cfm Maximum Noise Level 25 sones