58mm Diameter Ball Bearing Rope Sheave A replacement all-purpose rope sheave. Used throughout the complete Barton block range. Molded from UV-resistant acetal resin, the Barton sheave is made to survive the harsh marine environment. The unique, super-low friction ball race system features Delrin balls running on a large diameter center boss, which ensures an extremely low friction performance. Technical Specifications:Overall Diameter - 2- 3/10' (58mm)Hub Width - .71' (18mm)Bore -.24' (6mm)*Sold as an Individual