The Robelle Blue Mesh Winter Cover allows water to pass through into your pool while keeping out dirt and debris. This results in less maintenance during the winter months compared to traditional pool covers. Includes a three-foot overlap: less overlap is required for mesh covers because less pressure builds up on top of this cover. The Robelle Blue Mesh Winter Cover includes a heavy-duty binding around the entire perimeter of the cover: this prevents against wear and tear, keeps grommets in place season after season, and adds to the longevity of the cover. The dense mesh only allows water to pass through and will not lose its integrity over time. Two grommets are placed on center every four feet. With these grommets, you should use the included winch and all-weather cable to secure your pool cover. The Robelle Blue Mesh Winter Cover includes a ten-year warranty.