This 64GB micro sd storage card works just fine. Absolutely no issues, and looks like new, too! I ordered the first one to use in my new GoPro camera; it worked so well I then went head and bought a second one. Both work just like new ones. One question: Why do the 128GB cards have a higher write speed than the 64GB cards? I needed a V30-rated card for the camera, which this one is. However, I noticed on all brands of V30-rated (U3) micro sd cards that the write speed of the 64GB cards is about 60Mb/s, while the 128GB cards with the same rating have a write speed of about 90MB/s. Anyone know why this is?