Harken 125mm Runner Block — Becket - #3260Runners are used on running backstays of offshore boats to adjust mast bend for different wind conditions. Integrated sideplate bails and recessed cotter key help produce a smooth design that wont snag lifelines. 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.