Features: brand new and high quality Biochemical cotton bag filter provides biological filtration to the aquarium, helps to stable water quality. Good permeability, easy to clean. Increase the oxygen solubility. Perfect filters accessories for your for tank and aquarium. Working noiselessly, very durable, can be used for years. Specifications: Material: Biochemical Cotton Color: White Size: Approx.18x35cm/7.08x13.78in Weight: Approx.35g Note: 1.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1 Piece Aquarium Bag Filter