Package Contains: The package includes 16 CAT fountain filters and 16 sponge filters. The filters are individually packaged to ensure effective sealing of each filter. Scope of Application: Strong compatibility, our cat fountain filter can be compatible with 6 different models of stainless steel cat fountains 108oz / 32l and 67oz / 2l. Three-Layer Cyclic Filtration System: This alternative to the cat water dispenser filter contains activated carbon, which together with the wool forms a four-layer circulatory filtration system. It effectively filters pet hair, food debris, absorbs odors and softens water to provide your pet with fresh and healthy drinking water. Exchange Frequency: To keep your drinking water fresh and hygienic, it is recommended to change your water fountain filter every 2 to 4 weeks, depending on the number of cats in your home. Before replacing the pet fountain filter, rinse it thoroughly under running water and then install it in the cat fountain. Material Quality: