Individually wrapped activated post carbon replacement filter cartridge dedicated for iSpring high capacity tankless countertop reverse osmosis water filter system RCT600. As the last stage of RCT600, this post carbon filter removes chlorine, bad tastes, and odors to improve the quality of your drinking water. It captures any particles that may have accumulated before refreshing tasty water is delivered to the faucet. Quick and easy filter change. iSpring FT15B activated carbon Filter is built with secure push-fit quick connect fittings on both sides, allowing for faster filter replacement. If you have trouble installing the filters, please refer to the RCT600 installation video, user manual, or contact us directly. Depending on your water usage and the quality of your source water, please replace this activated carbon filter cartridge every 6-12 months to achieve optimal performance. Peace-of-mind after-sale support is backed by a 30-day money-back guarantee, manufacturer warranty, and lifetime free tech and customer support in Atlanta, GA. Register online to activate your warranty. We stand behind our products. Please feel free to reach out to us for questions and assistance. Your satisfaction is our top priority!