Product Description Replacement filter pack for the Aquasana Claryum® Countertop Water Filtration System (AQ-4000). Includes both filters needed for replacement (2-pack). Use only genuine Aquasana replacements with your Aquasana products - Non Aquasana brand replacements are not certified for performance capacity or contaminant removal. Replacements made easy - Simply remove the old cartridges and replace with new ones. The Aquasana Claryum® Countertop water filter (AQ-4000) is the most economical way to get clean, healthy water for your family. There's no need for an extra hole in your sink or permanent fixtures to enjoy great-tasting, filtered water. Simply attach the hose to your existing tap for on-demand filtered water. The system is space saving, only taking up a small amount of space on your counter. Water under pressure means filtered water, faster. Some water filter systems strip out the healthy minerals that naturally occur in water like calcium, magnesium, and potassium. The Aquasana water filtration system is uniquely designed to remove pollutants and reduce odor, while improving taste by preserving healthy minerals for optimum hydration. Full system WQA certified to NSF/ANSI Standards 42, 53 (includes P473), and 401 to remove 99% of 77 contaminants including lead, mercury, pesticides, pharmaceuticals, and more. From the Manufacturer The AQ-4035 is an updated replacement for the AQ-4025 The AQ-4035 cartridge set is a universal replacement for all Aquasana drinking water filters. The A and B replacement filters are guaranteed to be compatible with AQ-4000, AQ-4500, AQ-4501, AQ-4000W, AQ-4000P, AQ-4000B, AQ-4000N, AQ-4600 and AQ-4601. The AQ-4035 is our latest generation of replacement filters. We've spent the past 18 months redesigning and reformulating our filters to achieve our best filtration yet resulting in the new Aquasana AQ-4035 technology. The Aquasana AQ-4035 design and functionality are so unique, we've applied for a new patent. The drinking water filter set is the heart of all of our Aquasana drinking water systems. It features three distinct filter technologies: activated carbon, ion exchange and sub-micron filtration. Due to the unique manufacturing process, the Aquasana AQ-4035 filter is so densely packed with a sub-micron structure that water has to pass over 2.9 million square feet of contaminant grabbing media. That is how we achieve such high contaminant reduction rates. At the same time, the Aquasana filtration technology is selective, allowing naturally occurring healthy minerals to pass through minerals like calcium, potassium and magnesium. And that is why your water tastes so great.