[Compatibility] ONLY Compatible with PetSafe Aqua Fountain Aqua Cube, Aqua Fountain Aqua Falls and Current Pet Water Fountain. If any doubt, please check product dimensions. [Compatible Pet Filter] Length is about 2.5 inch. Width is about 2.5 inch. Thickness is about 0.18 inch. [Premium Quality Filters] Double Filtration System: Composed of a cotton layer and activated carbon. Effectively to filter hair, heavy metals, keeps water fresh and improve the taste of the water. [Frequency Of Replacement] To prevent the activated carbon dust from shedding into water, please soak the cat fountain filter in water for 2 minutes then rinse thoroughly under running water before using. 1 to 2 weeks in summer and 2 to 4 weeks in winter. If multiple cats are using the fountain, more frequent replacement will be necessary. [Premium 12 Pack Pet Fountain Filters] 12-pack of premium pet fountain replacement filters. Enough supply for 3 to 12 months of use. ONLY Compatible with PetSafe Aqua Fountain Aqua Cube, Aqua Fountain Aqua Falls and Current Pet Water Fountain. If any doubt, please check product dimensions. Length is about 2.5 inch. Width is about 2.5 inch. Thickness is about 0.18 inch. Double Filtration System: Composed of a cotton layer and activated carbon. Effectively to filter hair, heavy metals, keeps water fresh and improve the taste of the water. To prevent the activated carbon dust from shedding into water, please soak the cat fountain filter in water for 2 minutes then rinse thoroughly under running water before using. 1 to 2 weeks in summer and 2 to 4 weeks in winter. If multiple cats are using the fountain, more frequent replacement will be necessary. 12-pack of premium pet fountain replacement filters. Enough supply for 3 to 12 months of use. Please feel free to contact us if you have any questions about our products, we'd like to help you!