A great memory card, at a very good price. I recently upgraded to this memory card for use in my cell phone, and it has plenty of space to hold all of my music, videos, and photos. I can download as many songs as I want, and take as many photos (at the highest quality) as I want, without having to worry about the memory on my phone filling up.I have used SanDisk memory cards many times before, and I have always had very good experiences. It is still too early to tell if this card will live up to that standard, but so far, this memory card has worked very well for me.The Class 10 rating refers to the speed with which it writes to the card, and I have noticed that it is quicker than my previous micro SD card. As an upgrade and expansion to your smartphone's memory, I highly recommend this card!