Compatible: Compatible with flower fountains 1.6 - 3L. But not adapted to the Catit Fountain. Please measure the size of your fountain before purchase.Dimensions: outer diameter 125 mm, inner diameter 35 mm, thickness 10 mm. Improve the quality of the water: Three filtration methods can eliminate impurities. The outer polyester layer on each filter captures hair and debris. The three filtration steps ensure water quality and improve the taste of fresh cat water. Easy to use: Rinse the filter with water before using it, easy to mount on the fountain. Set of 8 in a box: Fountain Fountains Water Economic Chat. We recommend that you replace the filter every 2 to 4 weeks. Process 1, non-woven fabric and high quality cotton mesh, it effectively eliminates hair, debris and impurities in water , minimizes the threat of parasites. Process 2, high quality premium activated carbon, it is made from natural coconut hull, eliminates residual chlorine and other infectious microorganisms. Also eliminates odors, purifies drinking water and further improves taste, allows our pets to drink healthy water. Process 3, ion exchange resin, it eliminates the ions heavy metals and softens the water, allows our pets to love drinking water. The three filtration processes and the high quality cat fountain filter materials can improve the water quality and taste of freshwater. Wompatible with most water fountains of 1.6 L to 2.4 l. Note: Not suitable for the Catit fountain. Size: The outer diameter is 12.5 cm / 4,93 in The internal diameter is: 3.5 cm / 1.38 in Please check carefully if the filter size corresponds to your chat water fountain before buying. Individual PE bag for each Filter, long storage and more practical time. The 8-piece replacement filters are more worthy of your possession. Tips: 1, Rinse thoroughly The filter under running water before use. 2, the pet fountain filters must be changed every 2 to 4 weeks, depending on the frequency of use.