[EZ-Change #1 Aquarium Filter ]The filter cartridges are for EZ-Change # 1 Aquarium Filter, fit for 5-15 power filters. [Strong Adsorption Activated Carbon]Each fish tank filter cartridges contains a lot of high-quality activated carbon, which can effectively capture fine particles or dust in the water, removes the odors, water discoloration and impurities and provides water for the fish. [High-quality Filter Cotton]EZ-Change #1 filter is made of durable sponge filter and Fiber sponge filter, and then fixed by two layers of ultra high precision cloth, which can adsorb all kinds of debris and fish excrement, durable and long lasting. [Easy to Replace]You need to make sure your filter is a 5-15 aquarium filter. This filter cartridges come in pre-assembled construction, changes in seconds just shake and rinse. [Replace It Regularly]The EZ-Change aquarium filter is washable and reusable. It will affect the filtering effect if used for too long, so we recommend replacing it every 2-4 weeks. If the filtering workload is heavy, please replace it according to the actual situation. Material: plastic colour: blue Package Contents: 12 x filter element 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.