Features:Ultra-thin design, save space inside the aquarium tank, more beautiful. Comes with filter sponge, bio balls, air stoneinside, more surface area for beneficial bacterial to colonize and faster cycling, keep your fish tank clear and clean. Easy to set up: simply install an airline intothe unit and turn on the air pump, great way to clean and oxygenate your tanks; Easy to clean: simply squeeze the sponges in tank water. Easy to use: simply place it anywhere at the bottom of aquariumSuitable for shrimp tank, betta tank, breeder tank, goldfish, discus, guppies, fry, baby fish or other fish. Specification:Material: PlasticS: (Dia*H) 8*5.5cm / 3.15*2.17 inchL: (Dia*H) 10.5*5.5cm / 4.13*2.17 inch Package List: 1 x Aquarium FilterNote:Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering..