Mark R. Wietstock
I got my wife a Samsung Galaxy Tab 3 10.1 for Christmas, and it took awhile for her to start figuring out all the things it can do.  Once she did, that led, of course, to her wanting to watch movies on it.  That was my signal to spring into action, that is, if I wanted to prevent her from running wild, buying "digital copies" of every movie we already have in DVD or Blu-Ray.  You can't play DVD or Blu-Ray movies on this device, but you CAN use your computer's DVD or Blu-Ray drive and commonplace third-party software to convert movies in this format into ".mp4" and/or several other types of video files that CAN be played on this tablet.Since this particular tablet is capable of playing high-definition video (screen resolution is 1280 x 800 pixels), and we want to use ALL of that high-def capability, my conversion files tend to be pretty large (average 5 to 10GB per movie) ... way too big to be stored on the tablet's limited internal memory.  That's where the tablet's microSD slot ... and this SanDisk flash memory ... comes in.  I make HUGE mp4's, store them separately on a 1.5 terabyte drive, and then load as many of them as I can on this chip, which shows up in the tablet as a separate memory source.  Then all you have to do is pull up one of the movie files from the card, and hit play.  You can use the device's standard video player, or get an app with more controls.Watching high-def video on a tablet that's streaming the data from a memory card (rather than the tablet's internal memory) requires a memory card with very high "read speed," and this SanDisk card's "Class 10" rating fills that bill.  That's the difference between cheaper microSD that's primarily designed for simple data storage, and microSD that's designed for higher active transfer/read speeds.  The "Class 10" designation generally means that the subject card will transfer data at a MINIMUM rate of 10MB per second.  This SanDisk "Ultra" card is capable of transferring data at speeds of up to 30MB per second, depending on the speed of the device you're using it in, and other particulars of the way you're using the device."Frustration free packaging" means the chip, SD adapter, and plastic case comes in a little, sealed cardboard envelope with a pull tab opener.  This card comes pre-formatted for Android, and my use of it in the Galaxy Tab 3 for watching high-def .mp4 movies has thus far been flawless.Finally, don't let yourself get burned by counterfeiters in trying to save a buck.  While pricing on memory tends to fluctuate, Amazon's current pricing on this card is VERY competitive with any/all vendors out there selling GENUINE SanDisk "Ultra" memory.  Buy from Amazon, or other trustworthy vendor, because I just learned the hard way that these memory cards are being counterfeited in huge numbers ... that is, the counterfeiters are placing SanDisk labeling/packaging on inferior, generic microSD, and selling the bogus chips on Ebay and anywhere else they can.  I bought THREE from Amazon after I got burned by a Chinese seller on Ebay.  The counterfeit packaging and labeling was good enough to fool me, until I actually tried one of the chips in the Galaxy Tab 3 ... the write speed (that is, the amount of time it takes to transfer files ONTO the microSD card) was dramatically worse than the speed of a genuine SanDisk "Ultra" card, and the read speed was totally inadequate for playing movies on the Galaxy Tab 3.  I may never have figured it out at all if I didn't already have one other, genuine SanDisk "Ultra" with which to compare the fakes.If you want the best, most reliable memory for the microSD slot on your shiny, new Android device, look no further ... this is it.