1.Multi-filtration Functions: This small aquarium filter combines biochemical filtration, oxygenation and physical filtration in one. 2.Easy to set up and disassembled: All filter media of this product are replaceable and cleanable, include: sponge filter, filter stone, activated carbon, air stone. 3.Wide Application: Safe for fish, suitable for betta tank, shrimp tank, breeder tank, goldfish, guppies, fry, and baby fish tanks etc. 4.Mini Design:3.1x3.1x3.1 inch, Save space, more beautiful. This small aquarium filter is recommend for 1 - 20 Gal fish tank. 5.Super Quiet and Efficient: 4 suction cups at the bottom make filtration and oxygenation very quiet. Note: Need to connect with air pump and air tube (Not Included).