Is this the correct method to add different language mobile pages to a Hreflang sitemap?

<url>
<loc>http://www.example.com/</loc>
<xhtml:link rel="alternate" hreflang="x-default" href="http://www.example.com/" />
<xhtml:link rel="alternate" hreflang="pt-BR" href="http://www.example.com/web/BR/index.html" />
<xhtml:link rel="alternate" hreflang="pt-BR" media="only screen and (max-width: 640px)" href="http://www.example.com/mobile/br/index.html" />
<xhtml:link rel="alternate" hreflang="fr-CA" href="http://www.example.com/web/CA/index_fr.html" />
<xhtml:link rel="alternate" hreflang="fr-CA" media="only screen and (max-width: 640px)" href="http://www.example.com/mobile/ca/index_fr.html" />
<xhtml:link rel="alternate" hreflang="zh-Hans" href="http://www.example.com/web/CN/index.html" />
<xhtml:link rel="alternate" hreflang="zh-Hans" media="only screen and (max-width: 640px)" href="http://www.example.com/mobile/cn/index.html" />
</url>