Roaming is only available on the $28 /mo Base Plan.
Your Data Roaming Cap allows you to avoid nasty surprises at the end of your trip by limiting the Data Roaming expenses authorized during a given month. It is capped at $100 by default, meaning that you cannot spend more than $100 of Data Roaming in a given month. You can change your Data Roaming Cap to $300 or $600 directly in the Circles.Life app!
Please note that other types of roaming expense (SMS or calls for example) are not included in the Data Roaming Cap!