Hi Taken from https://superuser.com/questions/847016/performance-difference-between-sd-and-microsd-cards What I mean is, we might be lucky and have a card that whilst it isn't rated V90, seems to perform okay, we then buy 4 others the same and find they don't work reliably if at all. If it doesn't have V90 on it's label, then it isn't a V90 card, so whether it works or not is somewhat down to luck of the draw.  The card could also be so borderline, that it will work for the firs