Material and size100% brand new and high quality. Material: plastic + cotton; Size (D x H): 4.5 x 8 cm. FunctionProvides biological filtration to the aquarium, contributes to the stability of water quality. Increases oxygen solubility. Super Quiet Working quietly, good permeability, easy to clean. The super biochemical sponge filter features quiet operation and excellent filtration effect while oxygenating the water. Perfect FilterIt can clean sundries and stabilize water quality. water. Can cultivate useful bacteria useful to aquatic animals. This results in a cleaner living environment for fish, especially useful as a breeding filter or a secondary filter. Multi-layer sponge designMulti-layer sponge design, can be cleaned by sequence, the displacement of the cylinder not affecting the quality of the water. The water supply badly needed oxygen.