Water Fairy is often used in smaller aquariums, such as breeding tanks, small display tanks, etc.; large fish tanks can achieve the role of auxiliary filters Triple filtration and bacterial cultivation purifies water quality, filters fine impurities in the water, and decomposes fish feces to accelerate water circulation and stabilize the water quality of the fish tank Promote wave-making with high dissolved oxygen content, use air to form water flow, so as to achieve the function of adsorbing impurities and cultivating nitrifying , and increase the oxygen content in the water<br><br>No gas is discharged. Check the reasons: 1. Is the check valve installed upside down 2. The air pipe is seriously folded 3. Is the regulating valve blocked 4. The quality of the air pump Color: Black Material: ABS<br><br>Package Contents: 1 x Aquarium filter oxygen generator<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.