Compatibility and fit - Works with PETKIT drinking fountain Unit 3.0. Contains resin and activated carbon; replacement filters for Petkite Eversweet Solo 2/Solo SE/3 Pro/2S/3 & CYBERTAIL. Please check the model of your fountain before purchase to ensure the filter fits Water quality - Built with a cotton layer, activated carbon and ion exchange resin. This combination effectively removes hair and heavy metals and improves water taste. Keeps the water clean and fresh, helping your pet drink more and reduce the risk of urinary tract infections Triple filtration - Non-woven fabric filters pet hair and impurities, activated carbon adsorbs odors, and resin softens the water. This triple filtration helps your pet drink healthy water every day Replacement frequency - For best water quality, replace every 2-4 weeks depending on your pet's drinking frequency and the number of fountain users. Regular replacement keeps the water fresh and encourages more drinking Use scenarios - Multi-pet homes where several animals share the fountain - Homes with shedding pets to prevent hair from accumulating in the water - Health-conscious households aiming to improve hydration and support urinary tract health through better water quality