Panel Exhaust Fan Assembled Assembled Blade Diameter 20 in Blade Material Aluminum Drive Type Direct Drive Duct Diameter Not Applicable Exhaust Airflow @ 0.000 in SP 4 557 cfm For Cut-Out Width 22 1/2 in Frame Finish Zinc Plated Frame Material Steel Guard Type None Hazardous Location Class Class I Div 1 Group C and D Class II Div 1 Group F and G Housing Material Steel Housing Finish Galvanized Includes Hazardous Location Motor Includes Dehumidistat No