PLENUM FAN, WHEEL TYPE BACKWARD-CURVED, DRIVE TYPE BELT DRIVE, INCLUDES DRIVE PACKAGE YES, ASSEMBLY UNASSEMBLED, WHEEL DIAMETER 22 IN, AIRFLOW @ 0.250 IN SP 2,569 CFM, AIRFLOW @ 0.500 IN SP 1,644 CFM, MAXIMUM INLET AIR TEMPERATURE 104 DEGREES F, SHAFT DIAMETER 1 1/8 IN, BEARING TYPE BALL, SOUND LEVEL 5.3 SONES @ 0.250 IN SP AND 5 FT, FRAME MATERIAL GALVANIZED, WHEEL MATERIAL ALUMINUM, INLET DIAMETER 13 1/2 IN, ROUGH OPENING HEIGHT 30 IN