Inline Centrifugal Duct Fan Housing Material Galvanized Steel Fits Duct Dia 12 In. Voltage 120V Max Amps 4.8 Max Wattage 500 Number of Speeds 1 Housing Dia 17-7/8 In. Length 18-7/8 In. Motor RPM 1700 CFM @ Duct 2016 CFM @ 0.000-In. SP 2016 CFM @ 0.125-In. SP 1920 CFM @ 0.250-In. SP 1832 CFM @ 0.375-In. SP 1746 CFM @ 0.500-In. SP 1649 CFM @ 0.750-In. SP 1423 CFM @ 1.000-In. SP 1066 Max Inlet Temp 140 Degrees F Inlet and Outlet Dia 11-7/8 In. Motor HP 5/8