Harken MKIV Ocean Jib Furling System

Engineered for cruising yachts between 6.5 to 9.1 meters (21–30 feet), the Harken Unit 0 MKIV Ocean Jib Furling System delivers precision, reliability, and ease of use in a compact, lightweight design. Whether you're coastal cruising or pushing offshore, this system transforms headsail handling into a smooth, one-person operation. Crafted from hardcoat-anodized aluminum and fitted with high-load Torlon® ball bearings, the MKIV ensures low-friction furling and reefing without the need for lubrication. Its single-groove foil accommodates a 5 mm luff tape, making sail changes straightforward and efficient. The system includes modular extrusions for easy customization and a robust halyard swivel that maintains consistent sail shape while furling. With a total weight of just 5.9 kg (13 lbs), it minimizes weight aloft—enhancing boat balance and performance. The MKIV’s clean design and rugged construction make it a trusted companion for sailors who demand control, safety, and durability in every tack.

Designed for cruising yachts between 8.3 and 11 meters (27–36 feet), the Harken Unit 1 MKIV Ocean Jib Furling System delivers effortless headsail control with race-proven engineering adapted for everyday sailors. Whether you're coastal cruising or venturing offshore, this system allows you to furl and reef from the safety of the cockpit—without compromising sail shape or performance. Constructed from hardcoat-anodized aluminum and UV-stabilized for long-term durability, the MKIV Ocean features multiple rows of Torlon® ball bearings that eliminate friction and require no lubrication. The single-groove foil accommodates a 5 mm luff tape, making sail changes fast and straightforward. With modular extrusions and a robust halyard swivel, the system ensures consistent furling and reefing even under load. The Unit 1 system supports wire diameters up to 8 mm and rod sizes up to -8, with clevis pins sized for standard rigging hardware. It’s engineered to handle headstay lengths up to 16.12 meters (52'11") and includes everything needed for installation: foil sections, connectors, bushings, sail feeder, upper foil cap, lower drum, halyard swivel, Loctite, Allen keys, and reefing line. Please purchase the base toggle separately.

Harken MKIV Ocean Unit 2 – Part 7512.10 is designed for larger cruising yachts and is typically used in the 10.6–14.2 m (35–46 ft) size range. Harken's current Unit 2 installation data lists compatibility with 8 mm, 10 mm and 12 mm 1x19 headstays and -12, -17 and -22 rod. The lower toggle is not included and must be selected to suit the yacht's chainplate and forestay arrangement. Unit 2 toggle options are available with either a 15.9 mm (5/8") or 19.1 mm (3/4") clevis pin. If you are replacing an existing furler or are unsure which Harken unit or toggle is correct, please contact our rigging team before ordering. We can check forestay diameter, rod size, clevis-pin diameter and available installation length.

Engineered for serious offshore cruisers and performance sailors, the Harken Unit 3 MKIV Ocean Jib Furling System delivers robust reliability and smooth furling for yachts in the 45–60 ft (13.7–18.3 m) range. Designed to withstand the rigours of bluewater sailing, this system combines precision engineering with corrosion-resistant materials to ensure long-term durability and ease of use. Key features include: Single-groove foil extrusion for streamlined sail changes and reduced weight aloft. Torlon® ball bearings in both the halyard swivel and drum, offering low-friction furling without the need for lubrication. Hardcoat-anodized aluminum construction with UV-stabilized components to resist the harsh marine environment. Generous sail capacity and reefing control, ideal for handling large headsails in heavy conditions. Modular foil sections for easy installation and maintenance, with a sail feeder included for hassle-free hoisting. Whether you're cruising the coast or crossing oceans, Unit 3 offers the strength, simplicity, and performance needed to keep your headsail under control in all conditions. The MKIV Unit 3 Ocean Furling System comes without a Toggle. Purchase the base toggle separately.

Harken® toggle assembly accepts standard turnbuckle using swage, rod, Norseman®, or Sta-Lok® terminals. Toggle flips for fork or tang chainplate installation. A single stainless steel clevis pin provides access to the turnbuckle for adjustment. Sta-Lok® is a registered trademark of Sta-Lok Terminals, Ltd. Required to install a Harken MKIV Ocean Furler. Select by furler unit size and pin diameter.

Harken® toggle assembly accepts standard turnbuckle using swage, rod, Norseman®, or Sta-Lok® terminals. Toggle flips for fork or tang chainplate installation. A single stainless steel clevis pin provides access to the turnbuckle for adjustment. Sta-Lok® is a registered trademark of Sta-Lok Terminals, Ltd. Required to install a Harken MKIV Ocean Furler. Select by furler unit size and pin diameter.