The 5cm air stone ball dissolves more oxygen in water making your aquatic creatures healthier. Produces a steady stream of fine bubbles for your aquarium, fish tank and circulation system. Model: ASR-050B. Jet volume: 5 L/min, minimum pump power required: 2 W or 0.014 MPa. Suitable for 0.5cm ID air tubes Safe and strong: High quality non-toxic mineral material gives it a long service life and is not harmful to your fish. > Comes with 4 pack of 5cm Blue Air Stone Ball. 5cm Air Stone Ball - Blue This device creates a lot of small bubbles, which not only create a spectacular sight for the aquarium, but also provide extra oxygen to the creatures. Your fish will live in a healthier and cleaner environment. Besides, it is also made of good quality non-toxic materials. The stone is sturdy and durable, has a high dissolved oxygen level, and creates even, tiny bubbles rather than a limited number of large ones. Provides plenty of bubbles< /p> Suitable for 0.5cm inner diameter tube Easy to drive by 2W air pump Measures 5cm in diameter < p>Soak for about 1 hour