Tiny but Enduring: Each ball measures 0.8" D x 0.7" H and weighs 0.3 oz. Tiny but well-constructed for continual bubbling. Ideal for small fish tanks or aquariums. Medium Bubbles: The air stone balls produce a good amount of dense bubbles. A great way to increase oxygen solubility in your aquarium and enliven the aquatic lives. Model: ASR-020; Jetting volume: 1 L/min; Recommended air pump power: 2 W - 4 W; Standard ID airline tubing: 3/16". Efficient bubblers for long-time service. Reliable Material: Made of mineral material and sintered at a high temperature, it causes no effect to the health of your aquatics. Help keep your fish 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. The 0.8 inch air stone balls feature durability, steady bubbles and high dissolved oxygen rate. Optimal for aerating your water reservoirs and livening up your aquatics. A necessity to have in the house of aquatic lovers.