Compatibility - This cat water fountain filter replacement and water pump filter are compatible with the WF20/CF20 wireless pet water fountain. The size matches the original filter exactly. This pet water fountain filter provides a reliable solution for maintaining clean drinking water for your pet. Triple Filtration System - This cat water fountain filter features a three-stage filtration system that includes non-woven fabric, activated carbon, and ion exchange resin. This combination helps reduce odors, soften water, and improve the taste and quality of your pet's drinking water. The pre-filter sponge effectively captures pet hair, dirt, and food particles, helping to deliver clean and healthy water. Water Pump Filter - This cat water filter includes 9 high-density sponge filters designed to catch debris and hair in the water. These sponge filters help prevent clogging and protect the pump, contributing to a longer lifespan for the fountain's pump. Instructions for Use - To maintain clean and hygienic drinking water, replace the filter elements every 2 to 4 weeks depending on the number of pets. Before installation, soak the filter element in water and rinse for 2 minutes to ensure optimal filtration performance. The filter uses activated coconut shell carbon, which helps reduce heavy metals and residual chlorine in the water. Material: Non-woven fabric Color: White + Black Package Contents: 9 x Filter Elements 9 x Filter Sponge Note: The actual product may vary slightly in color due to lighting and screen settings. Measurement may vary by +/- 1-3 cm.