The Harken Fly Blocks with threaded fixing stand out for their great resistance and light weight. Specifically designed for technical ropes, these efficient pulleys display an exceptional workload for their compact size. The Fly Blocks are ideal for sport sailing yachts and foiling dinghies, as well as for the stepped haul-outs and backstay hoists of Grand Prix racing yachts.

The 18 mm models include stainless steel ball bearings with integrated central path and rivet, also in stainless steel, and are fitted with fiber-reinforced composite cheeks. The head of the double pulleys incorporates a guide made of composite materials which spreads the rope outwards in order to guarantee good alignment.