We have replacement GAC S7125 Filter and most other reverse osmosis water filters. This S7125 Premium Compatible is a post-filter replacement. It's a GAC, granulated activated carbon filter. These filters remove the taste and odor from your drinking water. It's considered a Goes Green Filter because it's a recyclable filter. If you have any other questions, contact us, 1-888-309-2837, and we'll help you find the right filter for your system.