According to the manufacturer, Multi-Wing H Series fans feature an airfoil profile blade that achieves greater performance and lower noise level than conventional, one-piece, injection-molded fans or metal-stamped fans. The materials of the H Series fans include injection-molded engineered thermoplastic or cast aluminum blades and pressure die cast aluminum hubs. These fans are available in 7- to 29-in. dia, in configurations from two to 14 blades with pitch angles from 25 to 45 degrees, says the company.