Medium Bubbles: The air stones with micro holes generate abundant dense bubbles around the cylinders, increasing oxygen and benefiting the aquatic life in your tank. Model: ASC100; Jetting volume: 5 L / min; Recommended air pump power: > 7 W; Fit for standard 5mmID tubing. Made from durable and washable silicon carbide. Larger Size: These bubblers are 10 CM in length and 5CM in diameter, which is fit for multiple occasions like hydroponic systems, ponds, aquariums, fish tanks etc. Stable in Water: Each cylinder weighs 0.36kg, which allows it to lie or stand steadily at the bottom of the tank when bubbling, providing a stable bubble release space. Easy to Use: Soak it completely in water for 1 hour before use. Clean by a brush as they get clogged after weeks or months of usage.