GLI Pool Products 20-2040RE-MSM-GRY-AC 20' x 40' Gray Max Shade Mesh Safety Cover. Designed to be stronger and more reliable. Max Shade Mesh will protect your pool against the most demanding conditions. A GLI Safety Cover is a safe solution for any homeowner. Not only will your backyard look great, but installation is easy and the “Peace of Mind” that you will carry throughout the winter months is well worth the investment.