The Watts Premier 531152 RO Pure 4 Pack Replacement Filters is a 4 Pack of filters that are designed to be used with Watts Premier's RO Pure Reverse Osmosis Systems. This filter is also compatible with Watt Premier's RO Pure Plus and/or Zero Pure Plus.
Filter Descriptions: 

• 5 Micron Sediment Filter (105311): Reduces the amount of sediment from rust, dirt and silt that would affect the appearance and taste of the water.
• 5 Micron Carbon Pre-Filter (105351): Reduces the amount of chlorine taste and odors and conditions the water before it is treated by the reserve osmosis membrane. Made with high quality activated carbon.
• 5 Micron Carbon Post-Filter (105341): Reduces the amount of chlorine taste and odors. Made with high quality activated carbon.
• 50 GPD Membrane (105331): Reduces a wide range of contaminants such as Arsenic, Copper, Nitrates, Perchlorate, Chromium, Lead, Dissolved Solids, as well as Cysts including Giardia and Cryptosporidium. Made as a semi-permeable membrane. 

Certifications:

• Certified to NSF/ANSI 372 Lead Free
• Certified to NSF/ANSI 58 Certified Reverse Osmosis Units
• Certified by WQA