Our Stack-style sail cover for your Bristol 27. This product is made from marine grade Sunbrella. Marine-grade Sunbrella is a material that has unparalleled performance because it is UV / Fade Resistant, Mold / Mildew Resistant, Bleach Cleanable, Sun Protection, and Breathable Comfort. Sunbrella stands behind their marine grade products with a limited ten-year warranty that covers color or strength loss from normal usage and exposure conditions, including sunlight, and mildew. All the fasteners are Commonsense Turnbutton Fastener Studs that are marine grade. All the zippers are YKK number 10. We use quality materials to build a cover that is meant to last.