Features 1. Our filter cotton is fully suitable for aquatic environments, without any chemical treatment, and will not cause harm to fish. For many years, we have been using this product in aquariums and ponds with significant results. This filter cotton works based on the principle of electrostatic adsorption - waste particles in aquariums/ponds will adhere to the filter cotton like they are attracted by a magnet. This filtering method can efficiently remove waste particles from water bodies. 2. This product is suitable for built-in filters, external filters, and pond filtration systems, and can be used for freshwater and seawater aquariums. When in use, simply use scissors to cut the filter cotton to the desired size. 3. The product is packaged in a large capacity self sealing bag with a slight compression design for easy storage. 4. Provide three types of filter cotton (10 * 0.1 * 0.025m, 10 * 0.12 * 0.025m, 10 * 0.2 * 0.025m) with different roll length specifications. Specification Product dimensions: 10 * 0.1 * 0.025m, 10 * 0.12 * 0.025m, 10 * 0.2 * 0.025m Package Include: 1 * Fish tank filter cotton