Two versions of this unit exist, an internal version and an external version.
The internal version can only be used on a B2000/1500 with 2 internal floppy drives, as it uses two leads which connect to a CIA chip. The unit takes timing from the CIA chip to ensure as perfect a copy of the source disk as possible. It's a combination of hardware and software which claims to be able to copy any normal density disk, particularly NON-DOS disks and disks which have copy protection. The software does not support multitasking, so you cannot work on something else whilst copies are being made. The hardware didn’t change over the years, but there were multiple revisions to the software.
The unit does not contain a switch, switch has been added by the user. Will not work in the A3000/4000 unless you can solder it to the CIA chip, since CIA is SMT mounted in these machines.