HWD 22in Pro Series TM Sand Filter Providing you with quality you can trust, the Pro Series high-rate sand filters incorporate the latest pool filter technology to ensure your pool is operating at its very best. Molded of durable, corrosion-proof reinforced thermoplastic, 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. Features Flange clamp design allows 360 degree rotation of valve to simplify plumbing Integral top diffuser ensures even distribution of water over the top of the sand media bed. Full-size internal piping provides smooth, free-flowing performance Unitized, corrosion-proof filter tank molded of rugged, colorfast reinforced thermoplastic for dependable, all-weather performance 7 position Hayward Vari-Flo™ control valve with easy-to-use lever-action handle lets you dial any of the valve/filter functions. Integral sight glass lets you see when backwash cycle is completed Large pressure sand/water drain for rapid winterizing or servicing Precision-engineered umbrella-fold self cleaning laterals for balanced flow and backwashing, plus easy serviceability