Compatibility - Cat fountain filter replacement is compatible with 101oz/3L crystal cat fountain. Please check the capacity and model of your fountain before purchasing. Triple Filtration System - The cat water fountain filter is composed of a cotton layer,activated carbon and an ion exchange resin. Effectively to filter hair, heavy metals. Improving the quality of the water so that pets can drink clean and healthy water. Pre-Filter Sponge - The pet fountain filter replacement includes 12 filters, 12 pre-filter sponges. The high-density pre-filter sponge can better filter hair and debris, preventing clogging and damage to the pump, and prolonging the life of the fountain pump. Individually Packaged - Baofum pet water fountain filters parts are individually packaged and sealed to ensure that the cartridges are not contaminated before use. Filter Size - Length is 4.72 inch. Width is 4.72 inch. Thickness is 0.39 inch. The pre-filter sponge: Length: 2.56 inch. Width: 1.18 inch. Height: 0.98 inch. Tips for Using - Please soak the filter in water for 5 minutes and rinse it thoroughly under tap water before use. It is recommended to replace the filter every 2-4 weeks to ensure clean drinking water for your pet. What You Get - 12 pack cat water filters & 12 sponges, worry-free 12 month warranty. If you have any questions about the filter, please let us know and we will reply within 24 hours. Cat Water Fountain Filter Replacement