The cross member side support closes the Sortimo TopSystem at the side and as a result prevents dirt from entering. The support serves furthermore as a side stop bar for the payload. That way e.g. the KG-pipes(floor pipes) or HT-pipes (high temperature pipes) will not roll off the roof when loading them up and you can very conveniently carry out your load securing. The aerodynamic form prevents unpleasant noise generation from arising.
The required installation material is included in the scope of delivery.
(pictures are similar, decorative material not included)