Product Name: Aquarium air stone; Suitable for: aquarium; Design: ring shapeMaterial: plastic, minerals; Ring outside diameter: 10 cm / 4 inchRing inner diameter: 7 cm / 2.8 inchPipe connection outer slide: 5mm / 0.2 inchNet weight: 69g;Ring moldColor: whiteDescription: Air stone can gradually release air in your aquarium, diffusing, eliminating the noise and the big bubbles of conventional air filtration systems, providing health benefits to the fish. Also a good decoration toolPackage: 1 x air stoneOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/-1-3cm.