Blower Wheel Type Backward-Inclined Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 24 1/2 in Airflow @ 0.250 in SP 13 940 cfm Airflow @ 0.500 in SP 13 745 cfm Airflow @ 0.750 in SP 13 544 cfm Airflow @ 1.000 in SP 13 336 cfm Airflow @ 1.250 in SP Not Applicable Airflow @ 1.500 in SP 12 900 cfm Airflow @ 2.000 in SP 12 430 cfm Airflow @ 2.500 in SP 11 915 cfm Airflow @ 3.000 in SP 11 340 cfm Airflow @ 3.500 in SP Not Applicable