The Lifegard Aquatics Uno+ Replacement Sponge Set (R440026) is a set of two sponges that fit all the models for Lifegard ALL-IN-ONE Pond Filter Kits. Each layer consists of two different grade sponges and this pack of replacement sponges allows you to replace the two sponges in each layer. It allows the user to always have a clean set of sponges when servicing the pond. Take out the dirty sponge from the Lifegard ALL-IN-ONE Pond Filter Kit and replace with a clean on.