• Replacement filters compatible with 3.2L/108oz stainless steel cat water fountains with water level window • Four-layer filtration system: non-woven fabric, activated carbon, ion exchange resins, and PP plastic housing • Combines adsorption, filtration, and interception to capture hair and debris, eliminate odors, and soften the water • Every drop of water is filtered through multiple layers, providing oxygen-rich and tastier water for pets • Helps increase water intake and reduce the risk of urinary tract infections • It is recommended to soak the filter before use and change it periodically to maintain clean drinking water • Includes replacement filters and pre-filter sponges