1.Quiet environment: This bio sponge filter creates a gentle flow without causing disturbance to you or your fish. 2.Green design: the bio sponge filter is green integrated design blends seamlessly with the green color of your fish tank plants, creating a harmonious and visually appealing environment. 3.Functions: this bio sponge filter has a mechanical filtration; it uses an air-driven system to generate suction that causes the sponge to capture particles floating in the water and return the filtered water to the tank. As a biochemical filtration, hazardous waste is converted into a relatively harmless substance by aerobic bacteria and accumulates in sponges. 4.Safe for small fish: with 60PPI fine bio sponge, it will never suck your breeding fish, keeping a crystal clear water tank. 5.Easy to set up & clean: simply install an airline into the unit and turn on the air pump, simply rinse and squeeze sponge in tank water.