Watts ETX-15 2.1-Gallon Non-Potable Expansion Tank for Hydronic Heating Systems<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>For use in closed-loop， non-potable water heating systems^2.1-Gallon capacity^Durable steel tank^60 psi maximum working pressure</li></ul></div><img src="http://ecx.images-amazon.com/images/I/31QfFxXqopL.jpg" noproxy>