Axial Upblast Roof Exhaust Fan Assembly Unassembled Drive Type Belt Drive Blade Diameter 48 in Base Diameter Not Applicable Base Length 56 3/4 in Base Width 56 3/4 in Base Shape Square Maximum Airflow 37 987 cfm Minimum Airflow 14 614 cfm Maximum Motor Horsepower 5 hp Minimum Motor Horsepower 1/2 hp Maximum Motor Speed 594 RPM Minimum Motor Speed 261 RPM Maximum Static Pressure 5/8 in wc For High-Static Pressure Applications No For Air Type Clean Air