Each template is a single HTML email built using Ink (Quickly create responsive HTML emails that work on any device & client). You can preview them and inspect the code to see how they were implemented, or download them and try making some changes. Each template already has Ink included in a style tag at the top of the file.
There are 4 different email layouts to download (e.g. Basic, Hero and Sidebar), you can see screenshots on Zurb’s website how each template looks on different email clients by viewing its tests. Note that if you are going to send or test them yourself, you need to run them through the Ink Inliner first.email templates