The 21 Second Backup used special hardware

Claims: The worlds fastest copier! It takes only 21 seconds to duplicate an original diskette, one keystroke provides the user with a complete backup. It works every time!

Also 21 Second backup will not work with the Burst Nibbler Cable. The program looks for this cable and will not work if the Burst Nibbler cable is found. This is because the cables are different.
This disk is VERY RARE and sells for over $100 when it pops up on Ebay.

Here is a link to a short Interview with the programmer of 21 Second back up

Here is the software and build notes of this kit: 21 second backup Plus