Made of high quality material? uniform air diffusion? beautiful and practical. Commonly? air stone is known as air diffusion stone? strong and durable? good air diffusion? good filtrability? widely used: 1 sewage treatment plant for aeration and agitation? to prevent deposition of large particles of sediments and remove part of organic matters. 2 fish ponds (aquaculture plants) increase oxygen for eutrophic water body in environment and biological culture. 3 increase oxygen for live fish and seafood transport. 4 aquarium (purifiers) purification and filtration; water quality ozone sterilization and oxygen increasing. 5 other processes need to diffuse air.Name: round shape air stoneModel: AS008Color: greySize: diameter 20mm5 x Air stone<br /><img src="http://img6.eachbuyer.com/x9/p100/by864_1.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/by864_2.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/by864_3.jpg" />