- Environmentally friendly filter cotton made from materials that meet ecological aquarium standards and are safe for direct contact with seawater and freshwater organisms. - Cuttable to fit your filtration system: size 2 meters by 12 centimeters; can be freely cut to match back filter, side filter, bottom filter tank, or filter barrel. - Reusable and durable: when dirty, rinse with clean water or rub gently to restore adsorption performance and reuse without damage or deformation. - Efficient dual-layer filtration: surface fine pore layer intercepts fine impurities while the inner coarse pore layer quickly guides the flow, balancing filtration accuracy with water flow speed and reducing blockage-related drops in efficiency. - Broad compatibility and practical sizing: suitable for common aquarium filtration setups and flexible enough to fit various configurations. - Use scenarios: - Freshwater community tanks using back or side filters that require reliable mechanical filtration. - Saltwater or marine tanks where material safety for organisms is important and direct contact is possible. - Larger or custom filtration systems, including filter barrels or bottom filter tanks, where trimming to fit is needed.