Hayward 18" Sand Filter W3S180T Pro Series high-rate sand filters are the very latest in pool filter technology. Molded of durable, corrosion-proof polymeric material, they feature attractive, unitized tank construction for years of trouble-free operation with only minimal care. Pro Series sets a new standard for performance, value and dependability. Applications Above-ground/on-ground pools Small in-ground pools Aquariums (salt or fresh water) Ponds Features Durable, corrosion-proof filter tank molded of color-fast material for long-lasting, all-weather performance. 7-position PermaGlass XL™ Vari-Flo valve provides maximum flow at lower pressure drop. Flange clamp design allows 360 degree rotation for easy installation. Integral top diffuser ensures even distribution of water over the entire sand bed for maximum use of the filtration area. Precision engineered umbrella-fold self cleaning laterals for balanced flow and backwashing, plus easy serviceability. Large pressure sand/water drain for rapid winterizing. We are a Authorized Hayward Dealer!