Superior filtration from the inside out - The Pro-Series filter features an integral top diffuser that evenly distributes unfiltered water over the sand media bed in a cascading, umbrella-like pattern. This allows the greatest filtration possible from every square inch of sand. Then the self-cleaning underdrain assembly, with its 360° slotted laterals, provides a fast, balanced flow of clear water back to the pool while allowing for more thorough backwashing. Best of all, the Pro's full-flow technology reduces your energy costs because the filter operates for shorter periods. Seven-position valve puts you in control - The patented, multiport control valve developed by Hayward was designed with seven pool filter positions. An easy-to-use lever-action handle lets you quickly dial any function. Long-lasting convenience - You can easily access the Pro-Series filter assembly for simple servicing via the unique folding ball joint in the laterals. A corrosion-proof housing protects the filter from severe weather for years to come.