Blower Wheel Type Forward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 9 in Airflow @ 0.125 in SP 1 621 cfm Airflow @ 0.250 in SP 1 540 cfm Airflow @ 0.375 in SP 1 471 cfm Airflow @ 0.500 in SP 1 408 cfm Airflow @ 0.750 in SP 1 286 cfm Airflow @ 1.000 in SP 1 160 cfm Airflow @ 1.250 in SP 1 006 cfm Airflow @ 1.500 in SP 689 cfm Airflow @ 2.000 in SP Not Applicable Airflow @ 2.500 in SP Not Applicable