Small Air Stone Cylinder: Measure 0.75" D x 2" H and weigh 0.86 oz. Tiny but well-constructed for continual bubbling. Ideal for small fish tanks, DWC systems or small ponds. Medium Bubbles: The air stones produce a good amount of dense bubbles. A great way to increase oxygen solubility in your aquariums and enliven the aquatic lives. Steady Output: Jetting volume: 1.5 L/min; Recommended pump power: 2.5 to 4 W; Standard ID airline tubing: 3/16". Efficient bubblers for constant air diffusion. Reliable Material: Made of mineral material and sintered at a high temperature, they won’t affect the health of your aquatics. Help keep your fish or roots growing healthily. Easy to Use: Soak the stone completely in water for 1 hour before use. Clean it regularly with a brush as it gets clogged after weeks or months of usage. Sintered with high temperature, they are well built to produce constant bubbles for fish’s breath. Perfect for oxygenation in both fresh and salty water environment like small buckets, fish tanks or aquariums.