Description: Made of plastic material, Durable to use and easy to replace. Effectively improve water quality. Cultivating the nitrifying bacteria, will give you superior biological filtration in your tank. This filter is noiseless and energy saving. These create numerous minute bubbles for increased oxygen flow. Simple and easy for filtering fish tank water, and keep tank water clean. Suitable for fresh or salt water types fish tank. Specification: Material: Plastic Cotton Size(LxD): Approx.4x4cm/1.57x1.57inch Overal Height: Approx.7cm/2.76inch Pipe Inner Diameter: Approx.1.1cm/0.43inch Package Includes: 1 Piece Fish Tank Filter Note: Since the size above is measured by hand, the size of the actual item could be slightly different from the size above. Due to the lighting effects, monitor settings, etc. There could be some slight difference in the color tone of the pictures and the actual item.