GLI Pool Products 20-1224RE-CES48-PRM-BLU 12 x 24 Rect Secure-A-Pool with 4 x 8 CES is constructed utilizing a monofilament fabric that is extruded using virgin resins along with yarns with the highest grade UV stabilization packages available. This time-tested fabric has been engineered to deliver high tensile and abrasion resistance properties for years of trouble-free protection. It also blocks sun, like a solid cover and that means that there is no springtime algae growth.