Muffins elements not available

I am working with Visual Composer in BeTheme, and like the option of using Muffin Composer items as well, as that seem to be an option. I really like the Zoom Box feature, but can't seem to find that particular item in Viisual Composer. There are a number of Muffin Builder items, although some items doesn't seem to be available while working in Visual Composer. Why?

See attached image.