Bought this unit in Sep 2012, finally got it setup in Dec. First time I used it, the neighbor came over and asked if I was doing some kind of construction. I live in a townhouse and the wall between the units are pretty thick, and I rarely hear anything from the next unit. I was really shocked how much noise this thing makes.
After a few days, I noised that something was loose inside the magnet unit. I took the cover off and found the screw and the plastic wheel has fallen off. I put it back on. This lasted another week, and something is loose and make the turning wheel stuck again.
I contacted the vendor and they politely told me that it's covered under warranty, but I will need to ship back the defective unit. Look at the weight and size, it would probably cause around $50 to send by UPS. I decided to throw it out and get another unit.
Don't waste your money and energy with this junk. Find something that can last more than a month.