Filter providing mechanical and biological filtration - Equipped with small diffusing stones, filters and bio ball filter materials to provide necessary oxygen to the water and ensure a quiet working environment This is an easy to disassemble filter The first separator is a sponge for mechanical filtration, the second separator is a clay ball filter for biology, the last layer is the base which is connected to the air hose. Innovative ultra-thin design: save aquarium space, more beautiful, filter dimensions: 7.1 cm x 8.1 cm Its working principle is to connect the filter with the air pump through the air hose, and the airflow from the air pump is injected into the filter. The vacuum air expels the water flow through the sponge and the clay ball to achieve the effect of water filtration and oxygenation. Wide ApplicationWithout fish hazard, suitable for shrimp ponds, breeding ponds, goldfish, discus, guppies, young baby fish or other fish