100% brand new and high quality Features: A great way to properly aerate a home aquarium, help to keep fish healthy and adds to the beauty of the aquarium. Increase oxygen levels, lower CO2 and raise pH It is an important instrument to successfully keep aquatic fish for respiration process Durable, washable and sintered by high temperature, different from other air stones Creates bubbles in fish tank while attached to an air pump Creates water currents and dazzling underwater scenes Easy and convenient to use. Usage: Before use, please immerse it in the water for 15 minutes. After a long-term use, clean your stone regularly so that it will be most effective. If the air stones just have bubbles in one part, please change a pump of higher power. Specification: Suitable for inner diameter 4mm soft tube. Material: Mineral, Plastic Diameter: app.2.2cm/0.87in Height: app.4.7cm/1.85in Color: Blue Quantity: 1 Pc Note: 1.Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 x Aquarium Air Stone (without retail package)