Compatible: The fountain filter size is 12.7 x 12.7 x 1.1 cm and the diameter of the center circle is 3.8 cm. Our fountain filter fits most 1.6-2.5 liter cat fountains! Please measure your fountain and check before ordering if the filter can be installed in your fountain. High Quality Material: The replacement filter uses natural woven non-woven materials, coconut shell activated carbon and ion exchange resin. It can catch pet hair and dust, it can effectively filter dirt and eliminate bad odor in water. Easy to Use: Just put the raised side up and the flat side down, easy to install. Please rinse the filter with water before using. You Will Receive: 10 pcs cat water fountain filter.The internal material of the filter increased by 30%.The raised material can help improve the efficiency of filtered water. Extend life and provide pets with clean water.