An External Page object embeds another website as part of a page's content.
You can embed an external webpage to one of your pages (Objects>External Page) or add it as a page on its own (New>External Link).
If enabled in the Preferences, Sandvox will use the address of the current web page in your default browser. The URL can be edited by going to the Object Inspector for an external page object or the page details section for an external link page.
You can change the URL of the page in Object Inspector. Also, change the size in the Metric Inspector.