Honest Opinion
I already had a SanDisk 16GB Class 4 card in my Android phone. Here is how you know this is faster: I'd press the Play button for the music player with the Class 4 and there was always a small delay before the music played. With this 32GB SanDisk Ultra, the music plays immediately. This is a very useful way to tell how fast this is. This memory card gets my Approval and my Thanks to SanDisk!