Check the listing for details. 600D Sailboat Mainsail Boom Cover Waterproof Tear Resistant Many Size Choices. Condition: New. Listed at 49.99 USD. 【Tight Fit】: Che Yi Bao's new Mainsail Boom Cover is equipped with a large zipper, a fixed rope, and an ABS carabiner to ensure that the product fits as snugly as possible to the mainsail after installation, so that it can be installed in one go without having to worry about wind and other natural factors affecting the tightness of the cover while waiting for you to use the sailboat again!【Tight Fit】: Che Yi Bao's new Mainsail Boom Cover is equipped with a large zipper, a fixed rope, and an ABS carabiner to ensure that the product fits as snugly as possible to the mainsail after installation, so that it can be installed in one go without having to worry about wind and other natural factors affecting the tightness of the cover while waiting for you to use the sailboat again!