[PERFECT MATCH]The water fountain filter is compatible with 100oz/3L Pet Fountain. With sponge filter for the pet water fountain pump. Keep Water Lasting : Exchange resin remove and calcium in water, and it is made into pet-friendly water (soft water) whose hardness is lowered; High performance activated carbon absorbs odor Easy To Use: Rinse the filter with water thoroughly before use, and replace it regularly (depending on the frequency of use). [PREMIUM QUALITY]Each pet fountain filter is composed of activated carbon, ion exchange resin and non-woven fabric. They can filter hair, heavy metals and improve the taste of the water so that pets can drink clean and water. [Recommendations]To prevent the activated carbon dust (caused by long shipping and will not harm your pets) from shedding into the water, please soak the filter in water for 2 minutes and rinse it thoroughly under running water before use. color: White Material: Cotton Package Contents: 12 x Water Fountain Filter 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.