Replacement Propeller Propeller Dia (In.) 20 in CFM @ 0.000-In. SP 4 350 cfm CFM @ 0.300-In. SP 3 760 cfm Min HP 1/2 hp Max RPM 1 140 RPM Pitch (Deg.) 33 Degrees CW Rotation Number of Blades 4 Propeller Material Aluminum Galvalume Spiders For Use With Air Conditioning Condensers Heat Exchangers and Unit Heaters Heat Pumps Requires Interchangeable Hex Hub 2A563 or 2A564 or 2A565