Medium bubbles: With lots of micro-holes which allow abundant dense and even bubbles to squirt out of the cylinder. A perfect way to completely aerate your water tanks. Larger size: measures 5 D x 20 L (cm). Suitable for large tanks like ponds, gardens, some large aquariums or DWC systems. NOT suitable for small aquariums. Model: ASC200; Spray volume: 24 L/min; Recommended air pump power: 7W; Standard ID Aircraft Tube: 4 or 8mm. Keep fish or roots growing healthy. Stable in water: Weighs 454g and comes with 2 square brackets at both ends to increase stability. It always remains stable in the water without moving easily when it bubbles. Easy to use: Soak it completely in water for more than 3 hours before use. Clean it regularly with a brush because it clogs after weeks or months of use.