It's a giant, fast micro-SD card for your phone. It works and it's reasonably priced. I've swapped this card through the past 3 phones I've owned and it continues to serve me well on the road. You can bring along enough 1080p movies for a 20 hour flight (or several of them) and still have plenty of room left over.The only downside is that it isn't even more capacity. But really, 64gb is probably overkill.