Description: *Dual-action filters: Resin and active carbon. Resin can soften water and reduce the chance of lithiasis. Activated carbon can adsorb impurities and odor, keep the water fresh and clean. PP cotton can filter out hair, sediment and debris to clean water. *Water quality can be removed by the three 3 types of filtration. The external cotton layer on each filter captures hair and debris. Three steps of filtration can assure the quality of the water and enhance the taste of fresh water for your cats. *Product raw materials: Food-grade filter cotton (Function: Filter cotton can effectively absorb large particles, sediment, slag stains) Food-grade microfiber filter cloth (Function: The use of microfiber filter cloth has a higher filtering effect, filtering micro particles and microorganisms) Using high-quality coconut shell activated carbon (function: purification, deodorization, organic matter removal, residual chlorine removal, and taste improvement) Baolite food-grade resin (Function: Resin absorbs calcium and magnesium ions in water (the main component of scale formation), reduces the hardness of source water, softens water quality, and can perform intelligent resin regeneration, remove metal ions that cause pet stones, and recycle (In order to fully remove calcium and magnesium ions in water, a water softening device must also be installed.) *Rinse the filter with water thoroughly before using, easy to mount it on pet water fountain. *In order to ensure the water clean, the filter should be replaced in time, please replace them within 2 to 4 weeks. Specifications: Name: Cat water fountain filter Inside material: Activated carbon, resin Size: Round style:Outer diameter: 128mm, inner diameter: 38mm, thickness: 8mm Square style:Outer diameter: 125mm, inner diameter: 33mm, thickness: 8mm Love style:120*140*20mm Package Included: 1* filter