[Premium Quality Filters] Triple Filtration System: Composed of a Sponge Layer and an ion exchange resin Layer. 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 10 minutes then rinse thoroughly under running water before using. 1 to 4 weeks in summer and 2 to 6 weeks in winter. If multiple cats are using the fountain, more frequent replacement be necessary. Compatible with for our 108 oz/3.2L Level Window Cat Water Fountain.Pet water fountains need to replace the activated carbon filter every 4 weeks and the foam filter every two months to keep the water fresh. Easy to replace, giving your pet even more protection. The first layer of filtration blocks hair and debris, the middle layer of filtration removes residual heavy metals, and the third layer of filtration provides healthier, high-quality flowing water, allowing pets to drink clean, fresh water throughout the day. Soak the filter in a clean bowl for 10 minutes. Note: The filter must be fully soaked before the fountain is turned on; otherwise, water may not diffuse through the filter and cause overflow. Do not soak the filter in the fountain tank to avoid dust. Quantity:9PCS Colour:White & Black Material:carbon fiber Package Contents: 9 x Replacement Filters 9 x sponge Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.