• The package includes 1 box and 4 filters for cat fountains, with individually sealed packaging to ensure filter cleanliness. • Exclusively compatible with 2.5L (84.5 fl oz) cat water fountains. • The triple-action filter is composed of cotton mesh, activated carbon, and ion exchange resin, which filter debris, eliminate odors, and soften the water. • Effective in filtering hair, heavy metals, and impurities, keeping the water fresh and improving its taste. • Rinse the filter thoroughly with running water for 3 minutes before use. • Replace the filter every 2 to 4 weeks to ensure the water is clean. • Provides clean and fresh water, increasing your cat's water intake and reducing the risk of urinary tract infections. • All filter materials have passed safety certification to ensure the highest quality and safety for your pet.