Pentair 180724 Stainless Steel FNS Almond Filter, 24-Square-Feet Filter, 48-GPM Filtration Area Six-position, top-mounted multiport valve Sturdy tank clamp of premium stainless steel has permanent spring mechanism to correctly indicate proper tightness for securing tank halves Water flows in bottom, up and around filter grid for even distribution of diatomaceous earth, eliminating bridging between elements and providing highly efficient filtration Exclusive grid assembly with molded-in handles lifts out easily for inspection and periodic cleaning Backwashes from top to bottom utilizing gravity for complete cleaning of accumulated dirt and D.E. powder