Amtrol ST-12 Thermal Expansion Tank<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Eliminates the waste of energy and water， thus saving money</li><li>Prevents a dangerous pressure build-up in the system</li><li>Prevents the relief valve from going off</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41XOHpu4%2BqL.jpg" noproxy>