Twin version, with two double inlet wheels on the same shaft, supported on light rectangular side frames of galvanised steel, screwed on the scrolls.  Ball bearings on electrically conductive rubber shock absorbers, inside inlet spiders.
Available from the size 160 to the size 630.
The standard fan can be freely rotated, to allow installation with orientation 0°, 90°, 180° or 270°, as defined in Eurovent 1/1.
