I will keep it short and sweet for potential buyers looking for facts and not b.s.I own two of the 32gb size of these cards for about 3 months now. They do work fairly well with cell phones and tablets, yet not so good with cameras, in fact these cards failed to work with my GoPro Hero3 camera and the customer service rep from Gopro claimed (and I happen to agree with him) that this card is not a true class 10 card let alone UHS-1.Benchmarks with my evo 4g with all allocation sizes the write speed never passed beyond 8mb/s while read speeds wondered around 25mb/s far below advertised speeds, well write speeds arent technically advertised (probably because they are of class 4 level)Benchmarks with crystal mark reported speeds even lower (due to adapter) with write speeds around 6mb/s while read speeds wondered around 20mb/s.Needless to say, if you are not worried about speeds and only about storage, these are perfect. If you want to use them for shooting high definition raw footage however, I suggest you not to loose your money on this, because even if your write speeds are around 10mb/s as the card begins to decay it will slow down to become useless.Again this review is based on GoPro camera and high definition raw recording.. For cell phones or for storage it works perfectly well with a bit of false advertisement..