Our silver cover has all the strength and durability to ensure years of winter protection. Heavier woven polyethylene scrim and coating makes our silver grade cover strong and able to withstand wind, sleet and snow. The cover is u. V. Stabilized to protect it from the harmful effects of the sun. It features a black underside to prevent algae growth and features heat sealed seams to ensure a crystal clear pool next spring. Our big 4 foot overlap means this cover won't stretch and rip like smaller 3 foot overlap covers. Our silver grade cover is held secure with a heavy duty vinyl coated cable and tightener that is anchored by rip proof metal grommets spaced 30 inches apart. This cover is backed by a 12yr warranty and is forest green with a black underside.