Dont make the same mistake as me....
I bought a "science museum" copy of these from Argos for £8, the first one lasted about 1 hour after taking it upto only 9000rpm and then the display stopped working and it became very rough, i took it back and got another one - the same thing happened. Got a refund from Argos and purchased the Powerball Neon Blue Pro from Play.com -
I was not dissapointed:-
Very smooth action which is quite relaxing at slow speeds and very intense at higher speeds.
The Display screen is of much higher quality compared to the cheap imitation.
Much better "grip" on the rubber ring around it - the cheaper ones had a hard plastic around it, which gave some serious cuts and blisters after a short period of time.
Lights look good, better in a dark room.
I found it easy to use from my first go, i have watched others try it and they do struggle at first, but once they get it going they dont want to give it me back!!
Go on buy it, you know you want to!!