Feature: 1. Active Cavity Structure: Bio media has light specific gravity, large surface area, high oxygen permeability, high water permeability and other characteristics. 2. Special Water Molecular Structure: It can quickly catch suspended particles, strengthen biodegradation, and facilitate the easy shedding of biofilms. 3. Safe: Fish tank filter ring provides efficient biological filtration and maintains a healthy aquatic environment without compromising water quality. 4. Beneficial to Biological Colonies: Biological filter media cultivates a good filter material for microbial nitrifying bacteria and preserves a large number of beneficial bacteria. 5. Scope of Application: Bio filter ring is suitable for both freshwater and sea water, suitable for most filters, fish tanks, aquariums, easy to use. Specification: Item Type: Filter Material Material: Probiotics Ring House Uses: Aquarium, Fish Tank Water Quality Filtration Beneficial Bacteria Environment House. Package List: 1 Bag x Bio Media