MiNi Air Driven Biochemical Sponge For Nano Small Betta Fish Tank Aquarium Corner Filter With Air Valve This mini corner filter comes with an air valve to help control the air flow from the air pump Good for small or nano fish tank Can absorb dirt, quickly resolve fish feces and eliminate smell in water, Help improve water oxygen level, need to combine with an air pump Dimension: 5.5 x 5.5 x 7.0 cm. (L*W*H) Package include: 1 x Corner Filter, 1 x air valve (Color is random and Air pump is not included)