GLI Pool Products ProMesh 20-2040RE-PRM-GRN-AC 20' x 40' Green Rectangle Safety Cover. This state-of-the-art cover material provides solid coverage benefits without any added weight. ProMesh covers come standard with stronger-than commercial grade springs on all custom covers which provides tighter, stronger security for your pool. If you open your pool in mid-spring and are looking for the benefits of a solid safety cover without the weight associated with it - this is the cover for you!