Hayward S210S ProSeries Sand Filter, 20-Inch, Side-Mount Pro Series sand filter delivers crystal clear water and requires minimal care Feature an advanced, self-cleaning lateral system for smooth, efficient flow, totally balanced backwashing and 6-position Vari-Flo control valve Tank is molded of corrosion proof polymeric materials for dependable all-weather performance Manual air relief for easy, manual release of air from system Measures 20-1/2-inch width by 32-1/8-inch height