Hayward W3S166T1580S 16" Polymeric Sand Filter System with 1 hp Power Flo Pump. Hayward Pro-Series filters are performance matched with an above ground Power Flo pump to ensure a system that maximized its filtration ability. The filter utilizes a precision engineered umbrella fold self cleaning lateral system to provide efficient flow and evenly distributed water for long lasting performance.Features:Durable, corrosion-proof filter tank molded of color-fast material for long-lasting, all-weather performanceFlange clamp design allows 360 degree rotation for easy installationIntegral top diffuser ensures even distribution of water over the entire sand bed for maximum use of the filtration areaEfficient, multi-lateral underdrain assembly with precision engineered, self-cleaning laterals gives totally balanced flow and backwashing