These actually work better than expected for such a cheap device. Sound quality and sensitivity is not great, a bit muffled, but good enough for their intended purposes. The transfer speed is slow, but sufficient for the audio files. They have more than enough memory space. Recording time is limited by the battery capacity, to several hours. Looks like many hours could be saved on the device. Plug in to a computer to recharge, save, and listen at the same time. Very small and unobtrusive. Easily records notes and conversations from a shirt pocket. Nice for all those sales calls that tell you that this is a recorded line. Now you have a recorded copy also! of course your mobile phone will do all this as well or better, but that is bulky and obvious, this device is not.