Medium Bubbles: The air stone produce abundant dense bubbles. A great bubble diffuser to increase oxygen solubility in your aquarium and enliven the aquatic lives. Airstone Model: ASB050; Jetting volume: 5 L/min; Recommended air pump power: > 4 W; Standard ID airline tubing: 3/16" or 3/8". Well-built and efficient for long-time service. Reliable Material: This air stones are made of mineral material and sintered at a high temperature. As essential air pump accessories for aeration in aquariums, DWC systems or ponds. Keep fish or roots growing healthily. Stable in Water: Each airstone ball measures 2" in diameter and weighs 3.75 oz. Well weighted to sink to the bottom and lie stably in your tank without floating up. Easy to Use: Soak the bubble 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 2 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.