MKIV Unit 0 Underdeck Furling Unit

Harken’s MKIV Underdeck Furling is the perfect solution for performance racers and cruisers who want an aerodynamic system with a minimal amount of equipment above deck. The drum is located beneath the deck, lowering the tack height for maximized sail area. The small outside drum diameter lets unit fit inside narrow bows.
Ball bearings between the center hub and deck bearing provide low-friction furling. The through-deck bearing minimizes water seepage into the underdeck compartment. The torque tube houses a full-length turnbuckle for optimal mast rake and tension adjustment.
The Unit 0 is a one-piece integrated deck bearing and line guard provides durability and corrosion resistance. It features an articulating ball joint, eliminating the universal joint and toggle to reduce weight and to simplify maintenance.
The Unit 0 furler and headstay are independent of each other, allowing flexible installation options.
The torque tube houses a full-length turnbuckle for optimal mast rake and tension adjustment.
Units 1, 2, and 3's Aluminum line guard, torque tube, and swivels are deep-saturation hardcoat-anodized for no-fade UV stabilization and durability. The hardcoat-anodized line guard is urethane-coated for additional corrosion protection.
The torque tube houses a full-length turnbuckle for optimal mast rake and tension adjustment. A torque tube universal joint on Units 1, 2, and 3 provides a high-strength universal connection to allow ample headstay sag when sailing downwind.
Units 1 and larger have self-locking threaded height adjusters for a correct fit between the chainplate and deck.
• No height adjuster needed
• Furler and headstay are independent of each other, allowing flexible installation options
• Small outside drum diameter fits inside narrow bows