A distinction is made between furling systems and furlers. Furling systems are only intended to reduce the sail area completely, i.e. full sail area or none. Distinctive feature: no foil stay. With furling systems, on the other hand, it is possible to reduce and increase the sail area continuously. This is achieved by means of a profile stay, a furler and a halyard swivel. The halyard swivel allows you to lower the headsail from the cockpit if you do not want to leave it completely furled. If a furling system is to be used for an existing sail, the sail must be modified by sewing on a new luff tape, which of course is only worthwhile if the sail is in good condition. The most common manufacturers of furling and reefing systems are: Harken, Furlex-Selden, Top-Reff, Bartels and ProFurl. These systems are available both manually and electrically or hydrically operated. For smaller systems, these will be operated manually for reasons of weight and cost.