Well, my knob finally broke. Something was getting wrong with it where it would barely turn at all, and then poof, now it spins freely. Supposidly you don't need the "stoppers" as it will still work. Sure, it still works wherever it broke free at, but the voltage isn't changing when i turn it, luckily it didn't break at a lower setting. Not sure this was worth the money now And all this time I've been telling people how great it is Wish there was a way we could fix it ourselves instead of spending $70 every 2 months on a new one cause it breaks that often....
They have a warranty, one of mine stopped working and I sent it back and they sent me a new one.