This page is using the Dropdown Navigation or Mininav.
The dropdown menu displays a simple dropdown for sub navigation elements. This style of menu can be set by including the .dropdown class in the <nav> element.
.dropdown
<nav>
Example: <nav id="navigation" class="main-navigation dropdown "> .
<nav id="navigation" class="main-navigation dropdown ">
In the template distribution this markup can be found in /ssi/navigation.html.
/ssi/navigation.html