Replacement Propeller Propeller Dia (In.) 18 in CFM @ 0.000-In. SP 2 490 cfm CFM @ 0.300-In. SP 1 482 cfm Min HP 1/5 hp Max RPM 1 140 RPM Pitch (Deg.) 27 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