I did hours of research into that product at one point and came to the conclusion that it is garbage. Tony nailed it, it's PVC with magnets taped around it with pretty packaging. This pretty much covers it all-
I worked with a woman who wrote speeches at Bank of America (for their government relations group). She was doing magnet therapy on her index finger. One day, she's screaming for help because she can't find her speech on the disk (back in the days when we had disks)...and I looked at her and broke into laughter. She wiped out a months of work on multiple disks with her magnet finger...quite hilarious.