Microporous design and airtight construction produce fine, evenly distributed bubbles to maximize oxygen replacement and reduce CO2 levels. Quality materials. The air bubble stone is made of high quality sand and plastic. Strong, durable, non-toxic and safe for fish. With long service life. Easy to use. Intake is compatible with standard overhead tubes. Connect to the air pump and put it into the water, helping the air pump to pump oxygen into the water. Widely used. The device is easily installed in hydroponic systems, ponds, aquariums, tropical fish tanks and more. No matter what problem you have, email me. I will answer you as soon as possible. If you are not satisfied with the product, we have no problem with the full refund. Features - Air diffuser stone, durable, good gas permeability , good filterability. - Increase oxygen levels, reduce CO2 and increase PH. Filtration and water quality ozone, sterilization and aeration. - Bubbles in the tank while connected to the air pump helps keep the fish healthy and increases the aesthetics of the aquarium. - You need more than 2W air pump to operate this stone. (not included). - If the dirt blocks and the air bubbles are reduced, you can remove the cleaning and use it repeatedly. Specification - Material: mineral, plastic. - Connection diameter: 4 mm. - Stone length: 11.6 cm. - Total dimensions: approximately 11.6 x 1.9 x 1.2 cm. Package Contents 3 x Bubble Bar Diffuser