Don't think that this company can sell you a 20TB Hard Drive which is 90% cheaper than any of the reputable sources we all know. 20TB Mechanical Hard Drives cost minimum £300+ at present
This is same as the SD Cards that said they were like 16GB but were just altered firmware on a 1-2GB Drive that flooded ebay etc 10yrs ago.
Try and copy even 20% of the stated capacity onto these drives and they cannot accommodate it.