Outdoor Water Solutions ARS0172 9-Inch Rubber Membrane Diffuser with Base<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Unit comes with a backflow valve and 1/2" fittings to plug into your 1/2" airline</li><li>Rated for up to 5 cfm and perfect for lakes or ponds， especially where you're only running one diffuser</li><li>Base can be filled with sand or gravel so it sinks to the bottom of your pond</li><li>ARS0172</li><li>Unit comes with a backflow valve and 1/2" fittings to plug into your 1/2" airline</li><li>Rated for up to 5 cfm and perfect for lakes or ponds， especially where you're only running one diffuser</li><li>Base can be filled with sand or gravel so it sinks to the bottom of your pond</li></ul></div><img src="http://ecx.images-amazon.com/images/I/31NU-2Oz1RL.jpg" noproxy>