Feature: 1. MANUFACTURING PROCESS: This aquarium filter mat adopts up and down weaving process, the middle layer is designed with honeycomb structure, and the micro porous structure enhances the water purification effect and filters small particles to a greater extent. 2. THREE DIMENSIONAL HONEYCOMB DESIGN: The three dimensional honeycomb design structure of the fish tank filter cotton increases the appearance area, which is conducive to the establishment and reproduction of the culture nitrifying bacteria system and assists in water purification. 3. EASY TO CLEAN AND CUT: The honeycomb woven structure design of the aquarium filter mat forms an excellent filtering mechanism, high strength and washing resistance, not easy to deform, simple to clean, and can be easily cut into any required size with scissors. 4. ENVIRONMENTAL HEALTH: This dual density aquarium filter media roll is virgin material and does not contain dyes. No spraying, no staining, good filtering effect, absolutely safe to all fish and other aquatic organisms. The material is sufficient, dense, thick, delicate and soft. 5. SCOPE OF APPLICATION: Our three dimensional honeycomb fish tank filter dense cotton is ideal for fresh or saltwater aquariums, and can be used as wet and dry filters, pumps, tank filters, waterway systems, etc. Specification: Item Type: Aquarium Filter Pad Product Material: Cotton Product Use: Filter Product Size: Approx. 100x50.5cm / 39.4x19.9in. Package List: 1 x Filter Cotton Note: Please allow 0.1‑1cm / 0.04‑0.4in error due to manual measurement. Thanks for your understanding.