Where high efficiency and quiet operation are required, the AID axial in-line fan offers an unrivaled solution. This innovative in-line fan is available in diameters from 12″ through 27″, with capacities ranging to 11,400 cfm. The AID axial in-line fan utilizes an ELTA adjustable pitch axial impeller for precise performance matching. The fan housing is constructed of heavy gauge steel and welded angle ring flanges. The motor base is constructed of welded heavy-gauge steel, and forms an integral part of the interior fan housing.