Aquarium decoration -Air stones for aquariums fish tank air diffuser Highlights generic brand Air stones for aquariums fish tank air diffuser Description: The air stone disc is suitable for your aquarium, fish tank and circulation system to obtain energy. oxygen. Made of stone, eco-friendly and durable, keep fish healthy and safe. The bubbles released by this gas stone are smaller, denser and more uniform, and the oxygen is dissolved in the water. The weight of the round aquarium air stone kit is enough to sink, easily placed on the bottom without a suction cup. The Stone Round Disc Air Diffuser is suitable for freshwater and saltwater. Size Chart: Style 1 Diameter: approx. 55mm/2.16inch Style 2 Diameter: approx. 85mm/3.35inch Style 3 Diameter: approx. 108 mm / 4.25 inch Thickness: approx. 40mm / 1.57inch Style 4 Diameter: 132mm / 5.20inch Thickness: approx. 40mm / 1.57 inch Package includes: 1 set of Air Stone Disc Bubble Diffuser Note: Please allow 1-3mm measuring deviation due to manual measurement. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. THANKS!