EHEIM Substrat Pro Biological Filter Media (Sintered Pearl-Shaped Glass) 450ml</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>Made of highly porous artifiical sintered glass material</li><li>Unbeatable surface area structure of 1800 sq ft per gallon</li><li>Can be reused by lightly rinsing with aquarium water every 1 to 3 months and replaced every 3 to 6 months</li><li>Provides longer intervals between required maintenance</li><li>Perfect size for Aquaball or Aquastyle filter</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/51JHe8CCN-L.jpg' noproxy></br><img src='http://ecx.images-amazon.com/images/I/31%2BISBNryJL.jpg' noproxy></br>