Description: It is one of the best kind of air stone for any hydroponic systems, ponds, fish tank, aquarium, creates an abundance of small tiny bubbles rather than fast or large bubbles, which is more suitable for shrimps and fishes breeding; Sintering in the high temperature, generating more oxygen and less CO2, with high dentity of bubbles comes out; Made of high-qualified, non-toxic, safe, eco-friendly material, no harm for water and for fishes; Creates air bubbles, aids in increasing oxygen levels, lower CO2 and raise pH. It is not just an important instrument to refresh the aquatic fish for respiration process, but it also can creat magic air curtain as an ornamental landscrape, very impressive; With 3 size for choice according to the size of your fish tank, it will be working with many kinds of air pump; Specification: Material: Mineral stone + Plastic 10cm-107x19mm/ 4.21x0.75inch, 139mm/ 5.47inch 13cm-132x19mm/ 5.20x0.75inch, 165mm/ 6.50inch 20cm-200x27mm/ 7.87x1.06inch, 242mm/ 9.53inch Package Includes: 1 Piece Air Stone Note: Due to the manual measurement and lighting effects, there is a slight difference between the size and color from the above and the actual item.