Blower Wheel Type Backward-Inclined Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 12 1/4 in Airflow @ 0.250 in SP 2 037 cfm Airflow @ 0.500 in SP 1 932 cfm Airflow @ 0.750 in SP 1 819 cfm Airflow @ 1.000 in SP 1 693 cfm Airflow @ 1.250 in SP 1 545 cfm Airflow @ 1.500 in SP 1 335 cfm Airflow @ 2.000 in SP Not Applicable Airflow @ 2.500 in SP Not Applicable Airflow @ 3.000 in SP Not Applicable Airflow @ 3.500 in SP Not Applicable