These handy water bags help hold your cover down in high winds and protect it from wind whip and damage. Our bags are made of heavy-gauge vinyl and are easily filled with water using a garden hose. They are designed to lie on top of the cover around the inside perimeter of your pool. Rugged grommets on top of each bag allow you to fasten them to your cover's cable. Use one bag every 2-3 feet. Anchor your winter cover this year with water bags!