Features: 1.Lightweight and easy to carry, perfect for using in fish tank, pond and aquarium 2.It can be used not only in biochemical filtration systems in seawater, but also in biochemical filtration systems in freshwater 3.When the water flows through internal space, prolonged the time, using the nitrifying bacteria to achieve the effect of biochemical filtration 4.Large volume, strengthened the effect of filtering bacteria 5.Great help to restore the natural water quality, and provide the most suitable living environment for your fishes Specification: The biochemical ball is lightweight and easy to carry. It can be used not only in biochemical filtration systems in seawater, but also in biochemical filtration systems in freshwater. Perfect for using in fish tank, pond and aquarium. Features: 1. Lightweight and easy to carry, perfect for using in fish tank, pond and aquarium. 2. It can be used not only in biochemical filtration systems in seawater, but also in biochemical filtration systems in freshwater. 3. When the water flows through internal space, prolonged the time, using the nitrifying bacteria to achieve the effect of biochemical filtration. 4. Large volume, strengthened the effect of filtering bacteria. 5. Great help to restore the natural water quality, and provide the most suitable living environment for your fishes. Specification: Item Type: Aquarium Filter Material Material: PVC + Sponge Color: Black Optional Type: 16mm, 26mm, 36mm, 46mm, 56mm, 76mm Quantity: 50Pcs Package Weight: Approx. 62-2410g Package List 50 * Biochemical Ball