The Bio House is a ceramic that has been heat treated over 1500 degrees Celsius. This amount of heat causes the ceramic to break its internal bonds thereby creating an extremely porous structure that has a much greater surface to allow very large bacteria populations to colonize. Due to the large quantities of tiny little holes, it gives the maxium surface of for the benificial bacteria to grow. FEATURE: -The BEST bio media available! - Highly porous ceramic material produces both mechanical and biological filtration - Larger surface to allow very large bacteria populations to colonize - Help clear clean water at a rapid rate by catching floating organic matter quickly - Emits FAR infrared rays allowing more oxygen to be dissolved in the water - Hollow design effectively distributes water flow - Suitable for both freshwater, koi pond and saltwater filters, good for trickle towel or wet and dry filter Dimension: 6.42" Long x 1.65" OD(outside diameter) Please note: Due to the nature of the product, we can not guarantee breakage during shipment, even if, it breaks, it will not influence the function of the product, and we will try our best to pack and ship.