Penn Plax Cascade 700/1000 GPH Bio Sponge by Penn-Plax</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>Pack of 4 Penn Plax Cascade 700/1000 GPH Bio Sponge</li><li>Convenient， no-fuss replacement sponge for your Cascade canister filter.</li><li>Optimizes the colonization of beneficial aerobic bacteria.</li><li>Removes ammonia & nitrites keeping your aquarium healthy.</li></ul></div></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br><img src='http://ecx.images-amazon.com/images/I/51seMFXLg0L.jpg' noproxy></br>