Single Line Reef is a familiar concept, but made practical and reliable by Seldén. All you do is ease off the halyard to premarked reefing points and then haul in on the reefing line. The luff and the leech are reefed at the same time.
A system of guided blocks inside the boom ensures that the lines do not tangle. The system has a 2:1 gear ratio, making reefing fast and simple, without having to leave the cockpit.