Do not buy this shake weight! I ordered one, used it twice, and the end popped out and nearly smacked me in the face! My mum also ordered one which came ALREADY broken!! It is cheap and nasty, and could cause great injury!
Now left severely disappointed and teased, as I could feel the burn from this workout!
Bought this for my wife to tone up her arms. She had a go and said it was "OK" so I had a try.
The first thing I noticed was the quality or lack of it. Cheap plastic which would benefit from having a rubber handle in my opinion. Very loose springs at each end for the weights to bounce around could have been better too with more movement of the weights.
Still, if you can keep a hold of it while jigging it about, I think you could feel the benefits of it.
Very average product and due to the quality, not quiet worth a tenner I'm afraid.