Coralife 2-Pack BioCube Filter Cartridge for Aquarium (12-Packs of 2)</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>THIS IS TWELVE OF THE THE 2-PACKS (24 Cartridges Total)</li><li>Replacement BioCube Filter Cartridge， 2-Pack， for all the Oceanic BioCube Aquariums and Coralife BioCube Aquariums</li><li>This is the Oceanic 8 BioCube Filter， Oceanic 14 BioCube Filter， Oceanic 29 BioCube Filter， Coralife Size 14 & Size 32 BioCube Filter & Coralife Size 29 & Size 32 BioCube Filter.</li><li>Coralife recommends， for optimum efficiency， cartridges should be replaced every four to six weeks</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/51QlE1-Y9aL.jpg' noproxy></br>