Harken 18mm Fly Block TripleHarken soft attach Fly blocks are designed to provide strength beyond mass, providing big power in a low aero package. Designed specifically for high tech line, these efficient blocks have an incredible working load for their small size. 18 mm blocks feature an integrated stainless steel inner race and rivet, stainless steel ball bearings, and composite fiber reinforced sideplates. Triples feature composite line guides that are integrated into the