I have asked both vendorsfor refunds.
On drivce was said to be a 128 GB.
The other was said to be a 250 GB.
Both drives created errors when I tied to use them in Widnows 10.
Windows XP can not format them.
There is a quuci test program I found that can test a drive in about ten minuetes or even less. This is much better tahtn try ing to fill the drive with data, which takes hours. The program is a real swiss army knife. Yu have to look over the documentation before it will work for you. Unless you are very smart.
RMPrepUSB is the anme of the program.
http://www.rmprepusb.com/I had to browse around and find the version needed.
The version is 2.1.732 and works in Windows 10.
You must quick format the fake drive before you test it.
This is the only program I found taht can do a test in just a few minuetes.
It does not test every bytem instead it looks for cross-talk from one block to anohter block.