Using in a Surface Pro's microSD slot.  I even reformatted to NTFS (which they claim is not recommended) in order to set up a virtual disk file on it and 'automount' that virtual disk upon startup so that my music library can be on this (Win 8 is kind of picky about letting you set up what it considers 'removable' volumes as directories to be auto-scanned for libraries, and this is one workaround.)Amazing to me that something the size of my pinky nail can hold my entire music collection at a nice high bitrate, and still have much more room left over.  One star off because its a tiny bit slow to write to but that might not be fair since I'm comparing to full-size SD and I did reformat, as I said.