The lightweight alternative to a block, with no moving parts, these are an extremely low-maintenance item. Unlike some other manufacturers, our rings are hard anodized with PTFE coating to provide the smoothest wear-resistant surface possible.The 38mm ring is mainly intended to create a 4:1 mainsheet system. Similar to our existing block combination, the EX1319, you can replace the 29mm Harken block by the 38mm Windesign ring. By changing this block, you create a low-friction, less heavy, and more durable block combination.The Windesign low-friction rings are available in 3 sizes and can be used in various applications.EX1314 Harken 40mm block on Vectran line with a safety snap shackleEX3003 Windesign 38mm low-friction ringEX13672 A bit of 2.2mm Vectran lineSpecificationRing diameter: 38 mmDimensionsOptiparts Low Friction Ring(38 mm)