Feature: 1. 100% brand new and high quality 2. Provides biological filtration to the aquarium, helps to stable water quality 3. Increase the oxygen solubility 4. Working noiselessly,good permeability, easy to clean 5. It reduces noise from air pump and consumes lowest wattage Specification: Description: 100% brand new and high quality Provides biological filtration to the aquarium, helps to stable water quality Increase the oxygen solubility Working noiselessly,good permeability, easy to clean It reduces noise from air pump and consumes lowest wattage Specifications: Color: Black Material: Biochemical cotton Style:XY-2830, XY-2831, XY-2822 Size: XY-2830: 14.59CM XY-2831: 1414CM XY-2822: 17*23CM Conversion: 1cm= 0.39’’ Notice: 1.Please use aquarium water to wash the sponge, don’t use hot water. 2.Please soak it with aquarium water for 5 minutes before use, It will be easy to digest bacteria colonies. Package Included: 1 * Biochemical Filter (Style base on your selection)