This group consists of an aluminium pressing with four blades. The diameter range is from 50mm (2”) – 150mm (6”) with various pitch angles and can be either clockwise or counter-clockwise rotation. Attachment to the motor shaft is by a set screw in the Zinc Plated steel hub. Bore diameters are from 4mm (5/32″) to 8mm (5/16″). Air volumes vary from 20m3/h to 750m3/h.