1,Biofiltration Filtration: The aquarium sponge filter uses biological filtration to convert hazardous waste into relatively harmless substances. 2,Physical Filtration: The aquarium sponge filter uses a sponge to catch floating particles through physical filtration and returns the filtered water to the fish tank. 3,Silent Operation: Aquarium soft biochemical sponge filter has a silent design, silent filtering, and no noise to the surrounding environment. 4,Custom Height: The aquarium sponge filter has a custom height that can be applied to more environments. 5,Premium Material: The fish tank filter is made of premium sponge and plastic, which is durable, not easy to damage and has a long service life. Item Type: Aquarium Sponge Filter Material: Sponge, Plastic Applicable Fish Tank: ≤350L 1 x Oxygen Pump Filter 4 x Raised Foot Mat 1 x Air Intake 1 x Air Outlet Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.