Fine bubbles: The air stone disc produces lots of medium dense bubbles. A great way to oxygenate your hydroponics systems, ponds, aquariums and animate aquatic life. Model: ASD100; jet volume: 12 L/min; recommended air pump power: > 4W; standard identification air hose: 4 mm. Durable material: made of mineral material and sintered at high temperature. Ideal for aeration in a DWC tank. Helps keep fish/roots healthy. Stable in water: measures 10cm deep x 2.5cm tall and weighs 198g. 3 strong suction cups easily fix it in the smooth aquarium, allowing it to rest securely in the tank. Easy to use: Completely soak the stone in water for 1 hour before use. Clean it regularly with a brush because they get clogged after weeks or months of use.