A Assembled/Unassembled: Unassembled , Base Height: 1.75" , Base Length: 38.75" , Base Width: 38.75" , Bearing Type: Regreasable Pillow Block , Blade Dia.: 30" , CFM Range: 7256 to 15,407 , Drive Type: Belt , Housing Material: Galvanized Steel , Max. Inlet Temp.: 120 Deg.F , Mounting Location: Roof , Overall Dia.: 40" , Overall Height: 30" , Propeller Dia.: 30" , Propeller Material: Steel , Requires: Roof Curb For New Installations , RPM Range: 454 to 964 , Shaft Dia. Sheave End: 1" , Speed Controllable: No