Sorted my back out

I bought the backballer for my lower back but when I used it I discovered that my upper back was agonisingly tense. The backballer relieves this so that it has been much better since. I now take it everywhere with me in case a long drive creates back tension. Getting the smooth model was a good idea as the standard one might have been too uncomfortable to use at first. My only suggestion is that the base be a little heavier as it sometimes moves around a little.