There are definitely some damaged cards out there so be wary and do not hesitate to call customer service
How is the product?
I bought two cards for tablets.  The first wouldn't format, so I bought another GSkill Class 10. The second worked, but only for 3-5 minutes. Then error, or freeze.  I thought it may have been the tablets.  However, the Gskill worked in both.....So I called Amazon.  The customer service was excellent.  There "may" have been a problem with one of their vendors......They shipped out two new cards with Saturday delivery.  It was "implied" through lengthy conversation with the Amazon Agent, that there were numerous problems with a particular company/vendor.Lesson:  Do NOT Hesitate To Call And Return if you get a card that seems to have ANY troubles out of the pack.I was surprised that my initial review was removed  from Amazon....So I am leaving another about the return.  II tried everything to fix these cards: fat32 ntfs and the newest exFat.....  There are definitely some damaged cards out there so be wary, and do not hesitate to call customer service! 