Adjustable Tack Swivel for ø13 mm AT-Cable, Seldén GX 15This accessory for Seldn GX furlers enables the sailor to easily trim the luff of the gennaker. The Adjustable Tack Swivel slides up and down over the AT cable and is handled from the cockpit with a down haul. As opposed to trimming the luff by slacking the halyard, the AT cable can now be permanently tensioned and always ready for furling. The sliding sleeve of the adjustable tack swivel consists of two halves and therefore it is easy to retrofit the