Compatibility - This cat water fountain filter replacement and water pump filter are compatible with the WF20/CF20 wireless pet water fountain. The size is identical to the original filter. Choosing this pet water fountain filter ensures seamless performance and convenience. Triple Filtration System - This cat water fountain filter features a triple filtration system including non-woven fabric, activated carbon, and ion exchange resin. It helps remove odors, soften water, and improve the taste and quality of your pet's drinking water. The pre-filter sponge captures pet hair, dirt, and food particles, providing 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. They help prevent clogging and protect the pump, extending the lifespan of the fountain’s water pump. Instructions for Use - To maintain fresh and hygienic drinking water, replace the pet water fountain filters every 2–4 weeks depending on the number of pets. Before installation, soak the filter elements in water and rinse for 2 minutes to ensure optimal filtration performance. The filter uses activated coconut carbon as the filtration material, which is safe and plant-based. It effectively reduces heavy metals and residual chlorine in water. Material: Non-woven fabric Color: White + Black Package Contents: 9 x Filter Elements 9 x Filter Cotton Note: Light reflection and differences in display screens may cause slight variations in color compared to the actual item. Measurement allowance is +/- 1-3 cm.