[Compatible]: Aquarium filter compatible with for ez-change # 3 aquarium filter, fit for 20-40, 30-60 power filters. [High quality Activated carbon]: Activated carbon can prevent odor, water discoloration and impurities from your aquarium, provide clean and water for healthier fish. [Strong adsorption]: Contains premium activated carbon, which can capture fine particles or dust in the water, removes the odors, water discoloration and impurities [Easy to install]: Easy to use, easy to replace and no need assemble, changes in seconds just shake and rinse. [Reusable]: The aquarium filter is washable . It is recommended to replace it every 2-4 weeks to that the water quality of the aquarium is clear. Material: filter sponge colour: blue Package Contents: 8 x Aquarium Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.