This item is well made of for durable and practical use. It effectively helps remove harmful and nitrite in the water. The tiny pores make it an home for beneficial to grow, which can provide a good environment for . Feature - Color: Black. - Material: . - Size: Approx. 10 x 10 x 10cm. - has a strong physical adsorption and chemisorptions role in the adsorption of certain organic compounds to achieve the removal efficiency. - The use of this principle, can quickly and effectively remove harmful in the aquarium water quality substances, odor, , and softening of the effectiveness of water quality, as well , etc., so that to obtain direct and rapid improvement in water quality. - This works faster, better, and longer than the rest. - Eliminates foul , unsightly discoloration, and harmful organic substances. - Made of material, durable and to use. Package list: 1 x