Triple version, with three double inlet wheels on the same shaft.  Version supported on strong rectangular side frames, made of galvanized steel, welded on the scroll sides.  Ball bearings on cast iron pillow blocks with grease points.
Available from the size 12-9 up to the size 30-28.  All sizes use hollow shafts, for higher stiffness.
The standard fan can be freely rotated, to allow installation with orientation 0, 90, 180 or 270, as defined in ISO 13349.
