Plenum Fan Wheel Type Backward-Curved Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 30 1/2 in Airflow @ 0.250 in SP 10 695 cfm Airflow @ 0.500 in SP 10 217 cfm Airflow @ 0.750 in SP 9 713 cfm Airflow @ 1.000 in SP 9 095 cfm Airflow @ 1.250 in SP 8 359 cfm Airflow @ 1.500 in SP 7 427 cfm Airflow @ 1.75 in SP 5 662 cfm Maximum Inlet Air Temperature 104 Degrees F Shaft Diameter 1 5/8 in Bearing Type Ball