I wanted to upgrade my 8gb microsd card for my Samsung Galaxy S3 with more memory. The SanDisk Ultra 64GB Micro Sd XC I class 10 memory Card works perfectly.  Recognizes with 59GBs available blank.  My Mp3s, Mp4s, WMVs, pyvs, etc. all play on demand and without delay or problem.  Amazon shipped it with trouble free packaging ahead of time using their free shipping option (USPS) and I couldn't be more pleased.  I highly recommend this memory card.