ataru13 saidWhat's wrong with it?
Nothing's wrong with it. It was a gift, right, so no need to worry about having spent money on it foolishly.
It takes strength to hold and wobble this piece of equipment...that's true. So if you use it you'll get some benefits. However, the claims made by the manufacturer are dubious (that you can do a shorter workout because you're doing "hundreds of reps" in the time of a regular exercise).
It's simply a fad exercise--like the shake weight, as someone said above--and you'll likely get sick of it and return to dumbbells, barbells, chin-up bars and squat racks.