Exhaust Fan with Drive Package Assembled Unassembled Blade Diameter 42 in Blade Material Aluminum Drive Type Belt Drive Exhaust Airflow @ 0.000 in SP 18 024 cfm For Cut-Out Height 44 1/2 in For Cut-Out Width 44 1/2 in Frame Finish Zinc Plated Frame Material Steel Guard Type None Includes Drive Package Includes Dehumidistat No Maximum Airflow 18 024 cfm Maximum Noise Level 17.8 sones