3 STAGE ULTRA FILTRATION SYSTEM: The Watts Premier Filter Pure UF-3 system was designed with you in mind. Capable of running at low water pressures, this system does not require a separate water holding tank, and does not require electricity. HIGHLY EFFECTIVE FILTRATION: This system kit includes one 5-Micron Sediment Filter for reducing sediment that affect the taste and appearance of your water; one LVOC Carbon Filter for reducing VOCs; one 0.1-Micron Hollow-Fiber Semi-Permeable Membrane. SMART DESIGN: The space-saving design allows this system to fit comfortably under your sink and requires fewer connections. It is also equipped with backflow prevention valves in the filter lid between cartridges, and double O-rings to prevent leaks. QUALITY CONSTRUCTION: With a maximum operating pressure of 85 psi, the included WQA certified filters are crafted from high-quality materials for maximum filtration. We recommend replacing pre-filters every 6 months and the UF membrane every 12 months. THE PREMIER DIFFERENCE: Since our founding in 1989, Premier has been dedicated to the design, development, and marketing of high-quality water filtration systems that exceed industry standards.