Works as specified, received in good condition from Amazon, using since a few months, in a smartphone, it doesn't get better than this if you're using Sandisk in terms of speed and space. You can expect speeds upto 28 MB/sec for WRITE, about 30MB/sec for READ, with the provided adapter, speeds ar always better for both read/write, using smartphone to read/write, speeds would be lesser mostly, but average should be 20mb/sec anyways as per what I've seen and I'm a heavy user, like if there is a 256GB microSDXC available, I would actually buy it, tried the Extreme version with 80mb/sec, costs 2 times of this one, but works similar to this, so dont waste money on name that doesnt deliver, buy this if you're buying to Sandisk