Difference between kayfuns?

So ib been googling trying to figure out the difference between the kayfun 3.1, and the kayfun 3.1es
And can only find info on the es

<img src="http://ecigfortmyers.com/wp-content/plugins/wp-o-matic/cache/1d00b6d8eb_sig-153231.jpg” border=”0″ alt=”” />

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