Abstract: The invention relates to sun protection installations comprising reflective sun protection lamellae consisting of portions having a toothed upper side disposed at least towards sun radiation influx wherein the individual teeth are formed of at least two tooth sides, and at least one first tooth side is, at least partly, exposed to sun light irradiation. Sun light irradiation, at least within the first lamella portions, can be retro-reflected by one single reflection into the outer space by the first tooth side having an angle of impact &agr;1. The tooth angle of impact &agr;1 of the tooth sides exposed to the sun light are so selected within the first lamella portions facing the irradiation area that in case of parallel sun light larger angles of impact &bgr; of the sun radiation are obtained so that inciding sun light may be reflected back, by one single reflection, to the outer space.