Medium Bubbles: Produces abundant dense bubbles to aerate your water reservoirs. A great way to increase oxygen solubility in your aquarium and enliven the aquatic lives. Model: ASD100; Jetting volume: 12 L/min; Recommended air pump power: > 4 W; Inner diameter of tubing: 3/16" or 3/8". Great for aquariums, DWC systems or ponds. Reliable Material: Made of mineral material and sintered at a high temperature, it causes no effect to the health of your aquatics. Keep fish or roots growing healthily. Stable in Water: Measures 4.1" D x 0.7" H and weighs 7 oz, which helps it sink to the bottom easily. And the 3 suction cups tightly suck the tank to make it sit stably in water. 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 4 inch air stone disc is optimal for oxygenating your aquatic environment and circulating added nutrition. It is a necessity to have around your house if you are a lover of aquatic animals.