Swap drives without the stress
Drives don't last forever. Mantle warns you when one starts to fail, shows what's only on it, and helps you move to a new drive safely.
Know when a drive needs attention
See health warnings from drives that report them, along with exactly which files have no other copy, while there's still time to act.
Move to a new drive, checked
Choose the old drive and the new one, and Mantle copies everything, verifies every file, then hands over. Keep the old drive as an extra backup if you like.