Forespar's Yacht Rod mechanical boom vangs are available in three sizes for boats from 30 - 55 feet in length. The internal spring provides boom support, while the block and tackle makes the Yacht Rod an excellent utilitarian vang for general cruising and club racing. Appropriate only for non-rotating, non-sliding booms and Yacht Rod/boom angles between 30 and 45. Angles outside this range will require an hydraulic vang. An incorporated 2:1 cable system doubles the purchase of the owner supplied block & tackle, which attaches to the vang. Do not undersize. Sizing boom vangs can involve many variables; we suggest you call for assistance. Eliminates the need for a boom topping lift (but main halyard should be attached to the boom when in port) Spring return supports the boom in light air, when reefing, and when lowering the mainsail Faster adjusting than hydraulics, with no messy hydraulic leaks or gas spring to lose its charge More efficient than conventional block and tackle soft vangs Complete sets include Yacht Rod, boom and mast fittings, and Harken block and tackle Note: When installing a Yacht Rod, you MUST use Forespar mast and boom fittings