Wide compatibility: 4-piece round box Size: 13 cm x 13.5 cm x 4.3 cm Weight: 71 g Effective Filtration: The filter contains activated carbon and ion exchange resins which help remove chlorine, odors and contaminants, effectively filter dirt, encourage your dog and cat to drink more water and favor animal health and hygiene. EASY TO INSTALL: Rinse the fountain filter 3-5 minutes before use. Keep the filter completely wet to remove carbon dust and keep the flat side up for optimal filtration. Then the installation is over. 2-3 Week Change: We recommend changing every 2-3 weeks to ensure the best protective filtration for our pets. TIP: Make sure the filter is the correct size for your fountain before purchasing and clean the filter thoroughly with water before use. If you have any questions about our products, please do not hesitate to contact us, we will serve wholeheartedly!