Value pack of 8 filters .The cat fountain filter are individually packaged and sealed to maintain high quality. Compatible with 84oz/ 2.5L elliptical pet fountain. Composed of a cotton layer,activated carbon and an ion exchange resin.They can filter hair, heavy metals, and improve the taste of the water so that pets can drink clean and fresh water, more healthier than other only have two filter materials. Our cat fountain filters provide clean, fresh water to your pet, which helps to increase water consumption and reduce the risk of urinary tract infections. Note: Rinse fiter with water before use. Replace fiter every 2-4 weeks.Worried about freshness of drinking water in fountain Worried about your pet getting sick No worries, Our cat fountain filter will solve your problem. Designed with upgraded Triple Filtration System that included activated carbon, ion exchange resin and cotton mesh. TIP Carbon dust or ion exchange resin may be released for the life of filter which is not harmful to your pet.