NSF 42 Certified CTO Purity MAX activated carbon block ï¬lters are the next generation in carbon block ï¬lter technology. With a higher filtration capacity than extruded ï¬lters, our coconut carbon ï¬lters are mixed, sinterized and compressed using advanced Celanese® resin. With an atomic mass of 3 million~10 million u, this patented Ultra High Molecular Weight Polyethylene (UHMWPE) resin also binds more carbon together than normal resins, maximizing carbon surface area and chemical absorption. This process increases the components capacity, removing more chlorine taste, odour and organic chemicals from the water than any other filter. Thanks to its 1 µm nominal rating, this ï¬lter also functions as a performance sediment ï¬lter. Competitively priced vs. extruded ï¬lters, CTO Purity Max is set to revolutionise the carbon block ï¬lter market. Due to their dual function, these ï¬lters can be fitted as either a Pre-Fliter or Post-Filter in RO systems, including stand alone or pump driven.