Amount : 8 pieces Medium bubble: The Airstone Disc produces dense, rich air bubbles. A great way to increase oxygen solubility and active aquatic life in your aquarium. Model: ASD-040; Injection volume: 2 L/min; Recommended air pump power: 2W - 4W; Standard trachea diameter: 0.5cm. Suitable for aquariums, fish tanks and small ponds. Reliable Material: Made of mineral material and sintered at high temperature. Ideal for aeration in DWC tanks. Helps maintain healthy fish or root growth. Water Stable: Each disc measures 4D x 1.8H (cm) and weighs 28.3g. Its rounded flat shape allows it to sink to the bottom and rest securely in the tank. EASY TO USE: Carefully soak the stone in water for 1 hour before use. Use a brush to clean it regularly as it can get clogged after weeks or months of use.

Note:Shipping time is 5-12 days