This is the most pseudo-scientific load of BS. If you buy one of these things, then you deserve to lose your money. I'm reminded of the saying "A fool and his money are soon parted."
As far as the balance test goes, I have run into this several times before. Con-men and liars have been using this trick for decades to sell pseudo-science products. Let me guess, it's the one where you stand on one foot, then they push on your hand to see if you tip over? It's complete shenanigans. When you're standing on one foot, your center of balance is obviously very narrow. Even the slightest change in angle of pressure will tip you over. The trick is very simple. When you're wearing the band, they push directly down on your hand. There is almost no angle. Then when you're not wearing the band, they alter the angle just slightly. It's nearly imperceptible, maybe they'll push down at a 2 or 3 degree angle. But that makes a huge difference in terms of your balance and center of gravity, and... you fall over.
Sometimes they do another trick with stretching. They'll have you stretch to your toes without the band, then put the band on and stretch again. And bam! It's magic, you're able to stretch farther the second time. However... this happens anyway! You can always stretch slightly farther the second time. The band has absolutely nothing to do with it.
Haha, "Proton Alignment Resonance Technology"... you have got to be kidding me.