1. Made of High - quality Materials: The mesh pocket is made of durable polyester material, which is strong and corrosion - resistant. It can be used for a long time without damage in the humid fish tank environment. The large - dense - hole design not only ensures good air permeability but also effectively prevents the leakage of activated carbon and filter media. 2. Multifunctional Filtration Aid: It can be used to fill with filter materials such as bacterial houses and activated carbon. When placed in the fish tank filter, it can efficiently purify the water quality, remove odors, impurities and harmful chemicals, and create a healthy living environment for fish. 3. Convenient Zipper Design: Equipped with a zipper, it is convenient to open and load or replace the filter materials at any time. The operation is simple and no complex tools are required, making the maintenance of fish tank filtration easy and convenient.