【Perfectly Fit】Only compatible with Aiimll 2L Pet Fountain. 【Premium 8 Pack】The pack includes 4 replacement pet fountain filters and 4 replacement pre-filter sponges. They are individually wrapped and sealed for optimal quality. 【Keep Your Pet's Health】Each filter is made of activated carbon, ion exchange resin, and non-woven fabric. They filter out hair and heavy metals and improve the taste of the water. This way, your pets can drink clean and fresh water all day long, which helps increase their water consumption and reduce the risk of urinary tract infections. Adding a pre-filter sponge around the pump can better filter impurities and extend its lifespan. 【Recommendations】To prevent activated carbon dust (safe for your pets) from spreading into the water, please soak the filter in water for 2 minutes and rinse it thoroughly under running water before use. 【Replace the filter regularly】 Depending on how often your pet drinks and how many pets use the fountain, please replace the