ITEM NAME:Aquarium Porous Ceramic filter media Net Bag- Biological ball fish tank X10 FT This is Breathing Bio Ball made by nano technology. The Bio Ball were Fired by high temperature. Great Material for the growth of nitrifying bacteria. Full of rich variety of natural elements and essential minerals and trace elements. Great help to restore the natural water quality, and provide the most suitable living environment for your fishes. Bio ceramic ball Specifics: Color: Yellow Size:21mm.Bio ceramic ball Specifics This is Breathing Bio Ball made by nano technology. The Bio Ball were Fired by high temperature. Color: Yellow.