In-Line Duct Blower Wheel Type Backward-Inclined Drive Type Belt Drive Includes Drive Package Yes Assembly Unassembled Wheel Diameter 18 in Airflow @ 0.000 in SP 4 680 cfm Airflow @ 0.125 in SP 4 549 cfm Airflow @ 0.250 in SP 4 412 cfm Airflow @ 0.375 in SP 4 269 cfm Airflow @ 0.500 in SP 4 127 cfm Airflow @ 0.750 in SP 3 760 cfm Airflow @ 1.000 in SP 3 290 cfm Airflow @ 1.250 in SP 2 523 cfm Maximum Inlet Air Temperature 160 Degrees F Shaft Diameter 1 in