Red Sea Fish Pharm ARE40260 Max Highly Porous Ceramic Filter Bio Media for Aquarium Filter Max Bio Media Is A Highly Porous Bio Media That Can Be Used In Most Filters Pore Structure Enables Both Aerobic Nitrification And Anoxic Denitrification Heavy duty square bottomed 1-mm mesh bag to be used when renewing biological filtration High Quality Ceramic Rings With 420 Square Meter Per Liter Or 1200-Square Feet Per Gallon Of Surface Area For Intensive Biological Filtration Great For Power Filters, Canisters And Wet/Dry Filters, The Media Comes In A Mesh Pack And Is Approximately 6-Inch Tall And 3-Inch Wide