Exhaust Fan Assembled Assembled Blade Diameter 20 in Blade Material Steel Exhaust Airflow @ 0.000 in SP 3 640 cfm Frame Finish Aluminum Frame Material Aluminum Guard Material Chrome Plated Wire Hazardous Location Class Class I Div 1 Group C and D Class II Div 1 Group F and G Includes Intake Guard Shutter Maximum Noise Level 29 sones