Designed for performance racing and cruising sailors, these strong, lightweight, aerodynamic systems are built for longevity, ease of use, and simpe installation. Installation is easy: C-shaped open connectors with low-friction plastic isolators slip onto the headstay wire and into the foil without the need to cut your headstay Twin grooves for fast sail changes: The foil's twin grooves and smooth feeder allow fast hoists, douses, and sail changes ideal for club racing. Installs over your existing turnbuckle: The drum install over the existing turnbuckle and is adaptable to a variety of rigging options. The Harken toggle assembly accepts standard turnbuckles using swage, rod, Norseman or Sta-Lok terminals, or fits directly to a marine eye and the turnbuckle body is accessible for adjustment by raising the drum. Other Outstanding Features The controlling dimensions for sizing Harken furling systems are headstay wire diameter and clevis pin diameter. Measure your boat's headstay length to determine whether a standard package has enough foils to build the unit. MKIV Unit 2 Particulars How To Order a Harken Furler Installation Instructions