Twin, strengthened 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.  Heavy duty bearings on cast iron pillow blocks.
Available from the size 20-15 up to the size 30-28.  All sizes use large diameter 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.
