This product is a built-in filter specially designed for fish tanks. It adopts a multi-layer filter design and has practical functions and can serve you well. It is mainly used as a filter material such as stone and environmentally friendly sponge, which can be connected with an air pump or a water pump to achieve the purpose of oxygenation and filtration, thereby reducing the death of fish. This is a very good filter and will serve you well. Features -Color:Assorted Color -Material: Filter Cotton, Plastic -Size: About 11.00X7.50X7.50cm/4.32X2.95X2.95inch -It has a reasonable structure design, which can save the space in the cylinder and is more practical. -With the functional design of multi-layer filtration, the corner filter can improve the solubility of oxygen. -Has a scientific design. It can not only perform mechanical and biological filtration, but also provide the required oxygen for water. -The efficient filtration system helps you maintain healthy and clean water quality, ensuring the health and vigorous development of aquatic pets and plants. -It is made with excellent craftsmanship, which is efficient and practical, and has excellent texture. Package list: 1 x Corner Filter