Blower Wheel Type Radial Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 19 1/8 in Airflow @ 1.000 in SP Not Rated Airflow @ 2.500 in SP Not Applicable Airflow @ 4.000 in SP 4 235 cfm Airflow @ 5.000 in SP 3 900 cfm Airflow @ 6.000 in SP 3 575 cfm Airflow @ 7.000 in SP 3 260 cfm Airflow @ 8.000 in SP 2 940 cfm Airflow @ 9.000 in SP 2 560 cfm Airflow @ 10.00 in SP 2 020 cfm Airflow @ 11.00 in SP Not Applicable