BLOWER, WHEEL TYPE FORWARD-CURVED, INCLUDES DRIVE PACKAGE YES, ASSEMBLY UNASSEMBLED, WHEEL DIAMETER 18 1/2 IN, AIRFLOW @ 0.125 IN SP 5,500 CFM, AIRFLOW @ 0.250 IN SP 4,780 CFM, AIRFLOW @ 0.375 IN SP 3,320 CFM, MAXIMUM STATIC PRESSURE 1/4 IN WC, MAXIMUM INLET AIR TEMPERATURE 140 DEGREES F, SHAFT DIAMETER 1 IN, BEARING TYPE BALL, SOUND LEVEL 7.6 SONES @ 0.250 IN SP AND 5 FT, 9.6 SONES @ 0.125 IN SP AND 5 FT, WHEEL MATERIAL STEEL, HOUSING MATERIAL S