Great feature that your bandwidth balance doesn't expire for a year, and it will rollover for another year if you refill.

Very useful for travelers, good coverage worldwide and greatest feature is that your data never expires (as long as you purchase a top-up once per year)

I liked this feature because I was able to store my AT&T SIM card in this little wallet so it wouldn't get lost while I travel (definitely something you don't want to lose).Also

Definitely would not recommend as it cost us time and headache while on vacation - just bite the bullet and pay for international plan with your cell provider

a T-Mobile data SIM and the Keepgo SIM.The AT&T SIM worked very well, was completely automatic and had 4G speeds, but was also by far the most expensive.