The Ion-X Pet Fountain Filters are expertly crafted to ensure your pet's water remains clean and fresh, contributing to their overall health and happiness. The unique dual filtration system combines the power of activated carbon and ion-exchange filters. The carbon filter diligently removes any bad tastes and odors, while the ion-exchange filter keeps the water soft, preventing mineral buildup. These filters are specifically designed for the PetSafe Outlast Pet Fountain and Viva Pet Fountains, providing a perfect fit and ease of maintenance. With a simple replacement process, these filters are designed for convenience and effectiveness. Your pet deserves the freshest water possible. Trust PetSafe to keep your pet healthy, safe and happy.