Harken 57mm Carbo Air Triple Block with Becket and 3-Way U-Lock allows a change of headpost direction Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming Low-friction Carbo Air blocks are lightweight, strong, reliablend affordable Lightweight nylon resin sideplates replace stainless steel straps found in Classic blocks. Densely packed glass fibers reinforce resin for strength Good for jib and mainsheet systems on high-performance dinghies, and for high-load control lines on small keelboats › See more product details