Flash drive received and performed the standard Windows quick format (exFat). The drive worked for about an hour when I put the data I wanted to back up on it. It was very slow when downloading data, although I should have used USB 3.0 (I don't think so). Then my computer couldn't read the flash drive and said it needs to be formatted? Annoyed I did another quick format but it didn't work so I took the drive to my laptop and this time did a quick format (NTSF). It seemed to work, so I started downloading the data to the hard drive. The next day, in the middle of downloading more data to a drive with less than 1% free space, this flash drive crashed again and said I needed to format it. Nothing I've done, unplug the flash drive, restart the computer with another computer made a difference. Even after another quick format, it still said it needed to be formatted.?! Here's the problem: I have sensitive data on the drive that makes me feel like I can't return it for fear it will be resold and someone could get my data. DO NOT BUY this item, it is of poor quality. I'll hit mine with a hammer and throw them away!