KX MATRIKX CTO filters are optimized for applications where they perform the role of both a sediment and activated carbon filter for chlorine taste and odor reduction. These filters are known industry-wide for superior performance. 5 Micron Nominal Filtration Rating (10 Micron Absolute Filtration Rating). Additional Details ------------------------------ Product description: The KX Matrikx 32-250-125-20, +CTO/2 Carbon Block is a water filter cartridge replacement that is NSF tested and certified to reduce and/or remove chlorine taste and odor in your drinking water. Powered by Greenblock technology, this carbon block filter also reduces organic compounds, sediment, and dirt through its 5 micron nominal/10 micron Absolute rating. This 20-inch water filter can be used in residential and commercial applications.