Durability warrantied for 12 years! The Blue Wave Silver grade cover has all of the strength and durability to ensure years of winter protection. Heavier woven polyethylene scrim and coating make this 12 Year cover strong and able to withstand wind, sleet and snow. Blue Wave covers are U. Stabilized to protect it from the harmful effects of the sun. It features a black underside to retard algae growth and heat sealed seams to ensure a crystal clear pool next spring. The Blue Wave 12-Year cover comes with loops every four feet to secure water bags, and corner grommets allow for extra tie down in windy areas. The cover is 5 feet longer and wider than the pool size, and comes in forest green with a black underside. Pool Size: 25-ft x 45-ft. Cover Size: 30-ft x 50-ft. Number of 8-ft water tubes needed: 18. Integral cover loops to secure water tubes. Protects against the elements. 5-ft overlap to ensure proper fit.