So they want you to send them your physical hard drive, presumably to assure themselves that the data has been erased...
But then they also want you to 'delete any data in your possession', so they already know that that is bullshit.
But then they also want you to 'delete any data in your possession', so they already know that that is bullshit.
See also: formatted with DragonFlyBSD's "Hammer" filesystem. Archived in BinHex. Saved with Base37 encoding. And 9-bit bytes. In the "/home/leopard/music" directory of a fresh Debian Potato install.
It's clear that they intend for it to be an otherwise clean drive, since the mention they're going to wipe the drive before returning it.
Again, they're not asking for any specific drive, just that you turn over a copy of all the data collected on a medium that's easy for them to use.