The Fluval 1 Plus Foam Pad has been specially developed as a standard filter medium for the Fluval 1 Plus Underwater Filter and maximizes surface contact between the water and the media. The large filtering surface ensures efficient cleaning of the aquarium water and maximizes the colonization of beneficial bacteria. - Polyester foam. - Performes both as a mechanical and biological media. - Maximizes surface contact between the water and the media. - Large filtering surface ensures efficient cleaning of the aquarium water and maximizes the colonization of beneficial bacteria. - 2 pieces per box.