Make sure when copying one hard drive to another that the target hard drive is as big or bigger than the original

It seems to have worked (the target drives all boot and appear to function perfectly) but this is by no means a surefire strategy, since technically the OS can use any part of the disk and you could end up with an incomplete target.

It must have had some issue with the source drive (Seagate 3TB) because I tried three different target drives and all failed.

The company states "Providing quick, yet complete hard drive cloning functionality, this universal dock can operate as a standalone HDD duplicator with no connection to a host computer, delivering an exact 1 to 1 clone of the target hard drive including partition and boot sector information, the Host Protected Area (HPA) as well as user data

Works exactly as it supposed to

I also feel it was way overpriced as I got one from a different manufacturer that does everything this one does, except erasing, for less than half the

At first I thought that it didn't work as it took

Just duplicated Quantity 5 - 500G hard drives