Round Leaf Net Swimming Pool Cover (30 Ft.) Made from durable woven polyethylene and carries a 4 year warranty- Extra 3-foot overlap and include a cable and winch to hold it securely in place over your winter cover. Black mesh fabric- Tight mesh traps even the smallest leaves before they reach your winter cover. **Other brands of leaf nets have larger mesh that allows small leaves to pass through to your winter cover and decompose