We had a swivel chair with the seat should be replaced. Since I had already suffered more under back complaints, we have adopted as an alternative to the above-mentioned these chair swivel stool eye. After purchasing the assembly was pretty easy. 2 components are plugged together and inflate the tire underneath the foot. Valve could be better reached. By constantly tilting and rocking motion back problems can be prevented. That is but one can not continuously sitzten on these 3 Hours / should. Up between, is always good. The 4 star gets the chair also in the first line, because similar Stool costs partly to quadruple this price and I think that this by the quality and range of motion is fully sufficient.