Review on 512GB-A High Speed Class 10 Micro SD Card with Adapter - Ultimate Storage Solution by Wagner Witlin

Spent the better part of 3 days transferring Kindle and MP3 libraries to the external card. I was finally able to download my Kindle books, but the Amazon MP3 transfers kept dying. The error was 240 "SD card not found" or "Unable to write to SD card". I was never able to transfer more than 11GB until the card shut up and blocked my music app. At one point, the card even reset the data, and what was available before disappeared. Not worth the $50 and not worth the headache and wasted time.