Features: 1Aquarium filter media set combines with a variety of filter materials, scientific and effective mixing ratio, makes fish tank filter works better. 2Biological filter can filter and purify water in all directions, improve the quality of aquarium water, eliminate impurities. 3It provides nice home for beneficial bacteria, encourages growth of biological colonies, which will create a suitable living environment for your fishes. 4Bio balls ceramic rings media works for any freshwater or saltwater fish tank or mini reef aquarium. 5Super filtration, good results, the filter material maintains the health of the water body by adsorbing dirt, germs, moss and other impurities. Item Type: Fish Tank Filter Media Material: Sand Gravel Soil Mixture Weight: Approx. 500g / 17.6oz Package Included: 1 Bag x Filter Material (500g) 1 x Mesh Bag