You buy 1 kg high quality ceramic ring bag (2 x 500 g). Our filtration rings are ideal for aquarium and pelvis filters. These filtration rings are packed in mesh bags - they are easily cleaned in the filter. In addition, they can be removed from the bag and placed in the filter. Large surface allowing bacteria to colonize and water to be biologically filtered by the removal of ammonium and Nitrites. Note: You will receive two 500 g net bags, which means that there will be 500 g per bag. See more details Color: White 1000g Content: 500 g x 2 (net packing). Compatible with: Culture of freshwater nitrate, seawater and grass. Product characteristics: Bacteria can exert great efficiency in the filter. The pore structure can be a good breeding bed to nitrify bacteria, create good water quality and reduce the frequency of water changes.