Powerballs - anyone tried them?

[BriocheDoree]

Just saw this on amazon and was wondering if they would be good for sensory seeking DCs that like spinning?
Anyone got one - are they any good?

DH has one (present from his mum). As I understand it, it's purpose is mostly to strengthen wrists and arms. It is quit heavy and a bit tiring you spin it round (you have to spin you wrist very quickly). I wouldn't say it is appropriate for a child (but I may be wrong...). Also I don't think it would help with sensory issues.