T-Mobile's International 1 Day Pass includes the following features for a period of 24-hours while traveling abroad:
You may purchase up to 10 international 1-day passes per line that can be used within a period of 30 days. After you consume all 512MB of high-speed data on your first international day pass, your second pass will automatically begin and the 24-hour period will restart.
Learn more about T-Mobile's international data passes here.
