» which advantages the ROOS®-solar ribbed tube provides?
» how simply the collector is fastened ?
» that it is storm-proof ?
» about its advantages when it rains ?
» why there is no risk of calcareous deposits ?
» why it is dense under pressure and vacuum-proof ?
» why it is not attractive for rodents ?
» why you should neither insulate it nor cover it with glass ?
» the weight of the collector ?