Blower Wheel Type Backward-Inclined Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 15 in Airflow @ 0.250 in SP 4 402 cfm Airflow @ 0.500 in SP 4 289 cfm Airflow @ 0.750 in SP 4 170 cfm Airflow @ 1.000 in SP 4 048 cfm Airflow @ 1.250 in SP 3 921 cfm Airflow @ 1.500 in SP 3 789 cfm Airflow @ 2.000 in SP 3 506 cfm Airflow @ 2.500 in SP 3 176 cfm Airflow @ 3.000 in SP 2 720 cfm Airflow @ 3.500 in SP Not Applicable