The Fluval Ceramic CO2 Diffuser Disc is a replacement part for the Fluval 88g CO2 Diffuser. It is ideal for use in planted nano aquariums, including Fluval's Flora Aquatic Plant Kit. The diffuser helps to effectively dissolve CO2 into your aquarium. The Fluval Ceramic CO2 Diffuser Disc will help to properly ensure your fish live in a healthy and safe environment.