Blower Wheel Type Forward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 20 in Airflow @ 0.000 in SP Not Applicable Airflow @ 0.100 in SP Not Applicable Airflow @ 0.125 in SP Not Applicable Airflow @ 0.250 in SP Not Applicable Airflow @ 0.375 in SP Not Applicable Airflow @ 0.400 in SP Not Applicable Airflow @ 0.500 in SP Not Applicable Airflow @ 0.750 in SP 12 150 cfm Airflow @ 1.000 in SP 10 230 cfm Airflow @ 1.250 in SP 7 650 cfm