Pentair 180009 FNS Plus Fiberglass Reinforced Polypropylene Material, Vertical Grid, D.E. Pool Filter, 60 Square Feet, 120 GPM Chemical-resistant fiberglass-reinforced polypropylene tank for exceptional strength and long life Easily removable filter grid pack is secured by a single nut to simplify maintenance Unique internal design ensures optimal filtration and backwashing efficiency for longer runs between cleanings Operating limits maximum continual operating pressure of 50 psi. Curved vertical grids provide maximum filter surface area for better cleaning This Filter has a conveniently located 1-1/2-inch drain for easy and efficient cleanout; measures 22-inch length by 50-inch height by 22-1/2-inch width