It works as advertised if you don't try to get too clever. I wanted to take a short cut in copying off all my files from my old 32g microSD to this one, so I could use it in my samsung galaxy tab 7.7. First thing I did was put it in the galaxy tab and format it - 59gigs was yielded. Great so far. Then I used two separate card readers in an attempt to copy the files from the 32g to the 64g card. The computer prompted me, telling me that the new card needed formatting, and asked if I wanted it formatted to fat32. So, I clicked yes; although I couldn't understand the prompt, since I had JUST formatted the card using my tablet. Thats when the effluent hit the fan, cause the computer froze in the attempt and that microSD hasn't worked on either my laptop or my tablet since.