Self-contained sheaves are designed for sailors to use in custom applications. Big Boat and high-load sheaves are available for special applications as well as for replacement sheaves in Big Boat blocks. Narrow high-load sheaves in mastheads improve sail handling, speed sail changes, and allow the use of smaller, lighter halyard winches. High-load titanium V sheaves feature the same incredibly efficient bearing set of angled titanium rollers as Harkenís V blocks. Perfect for running lines underdeck, in mainsheet and spinnaker sheet or drop line systems. They are also perfect to rig clean backstay systems to steady todayís slender masts and adjust mast bend.