Replacement Propeller Propeller Dia (In.) 18 in Bore Dia (In.) 1/2 in CFM @ 0.000-In. SP 2 145 cfm CFM @ 0.300-In. SP 880 cfm Min HP 1/12 hp Max RPM 1 140 RPM Pitch (Deg.) 19 Degrees CCW Rotation Number of Blades 2 Propeller Material Aluminum Galvalume Spiders For Use With Air Conditioning Condensers Heat Exchangers and Unit Heaters Heat Pumps Requires -