This filter cotton is well made of premium material for durable and practical use. It can be used in sea water tank, fresh water tank, aqua-plant tank. Fine hole design is easy and useful to filting. And its strong filterability can stable water quality and reduce fish died. Feature - Color: As Shown. - Material: Cotton. - Size: Approx. 45 x 25 x 1cm. - Effective to avoid residue and reduce the death rate of fish and chemical filtration and increase the oxygen solubility in aquarium and fish tank. - Strong filterability. It can be used repeatedly after cleaning. - Fine hole filter cotton is useful and effective. - Suitable for sea water tank, fresh water tank, aqua-plant tank. - Great fish tank and aquarium filter cotton and give the fish fresh environment.