Series 30 Utility Ball Bearing Block - Single, Swivel Shackle HeadFeatures: Low friction 2-stage ball bearing system provides consistent performance over the full working load range. High static and dynamic load capacity. Light weight Versatile head fittings Product Information:Sheaves running on Acetal or TorlonA(R) ball bearings provide high performance & low friction. The 2-stage ball bearing system provides consistent performance over the full load range.Can be fitted with a shackle in either of two planes to allow correct alignment of the block.Applications: Primary lead blocks on dinghies and catamarans Control lines on larger yachts Materials: U.V. stabilized Acetal sheaves Acetal ball bearings Impact modified, fiber reinforced and U.V. stabilized Nylon cheeks Grade 316 stainless steel load straps and head fittings .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }