I saw that too... I've seen "MadMag" and "MaxMag" before that did the same thing. Once upon a time, somebody had some of these knockoffs and they were actually magnetically slightly stronger than Geomag. But I've seen reports of MadMag where they are hollow and are useless. I have also bought a knockoff that was the exact same size and claimed to be the same strength but it was much weaker (and MUCH lower quality control on the plastics).
If this Hotmag was cheap enough I'd buy a set to see how it compares, but at the price they want on eBay, I'm not interested. I'd much rather buy the real thing.
And stay away from eBay. By bidding you're increasing the prices I have to pay
.