BF-4 spreader boots from Sparcraft are protective covers designed to fit over Isomat BF-4 spreader tips, helping prevent sail chafe and extend the life of both sails and standing rigging. Typically made from durable molded plastic or flexible vinyl, these boots create a smooth, rounded surface that reduces friction as the sail passes across the spreaders during tacks and gybes. They are engineered to fit the larger BF-4 spreader profile—commonly used on mid- to larger-sized rigs—and can accommodate various rigging configurations, including continuous and discontinuous setups. Easy to install and built for marine durability, BF-4 spreader boots are a simple but essential upgrade for maintaining sail performance and protecting critical rigging components.