Check the listing for details. 5x 2cm Fish Tank Aerator Mineral Bubble Release Aquarium Air Stone Diffuser Safe. Condition: New, Made in China. Listed at 11.25 USD. 5x 2cm Fish Tank Aerator Mineral Bubble Release Aquarium Air Stone Diffuser Safe Note: soak in water for 15 minutes before use. suitable for inner diameter 3mm-4mm soft tube Package includes: 5x air stone Material: ore Color: random Dia: 2 cm/0.78 in Features: *Ozone aerated stone, bubble stone, using super hard gold steel sand, after high-temperature sintering, good gas diffusion, good filterability, ozone resistance, corrosion. *Increase oxygen levels, lower CO2 and raise PH, creates water currents *It is an important instrument to successfully keep aquatic fish for the respiration process. *Durable can be reused and washed repeatedly. *Creates bubbles in a fish tank while attached to an air pump(air pump and air tube are not included). SKU: 238-186/DDD NN.