Twin version, with two 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 9-7 up to the size 30-28.  Sizes from 18-13 upwards 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.
