57 mm Black Magic Aluminum Stand-up Block, Harken 3227

Black Magic Air blocks are a top favorite of Big Boat performance racers and cruisers. These lightweight, free-running, powerful performers are used for sail controls that see lots of action. Sideplates and sheaves Hard Lube-anodized for maximum UV protection and a smooth surface. Center cage keeps Torlon? roller bearings separated and parallel to reduce friction. Torlon is a registered trademark of Solvay Advanced Polymers L.L.C.