I-Frames insert another HTML document onto an editable surface - such as the Google map fragment shown above.
In most practical uses the 'parent' page provides some HTML to insert into the source view of the page.
<iframe frameborder="0" height="300" marginheight="0" marginwidth="0" scrolling="no" src="https://maps.google.com/maps?hl=en&ie=UTF8&ll=40.759505,-73.984669&
This is shown on the neatComponents surface with a placeholder 'IFRAME' marker until the surface or page is saved, when the remote HTML contents are rendered.
You simply need to flip the Text Editor to Source mode, insert the HTML in the required location, revert to the graphical editor view, and Save.
The I-Frame location can be in line-of-text, or set using a Table or by using <DIV> positioning