Perhaps one of the most important industry advancements has been the 3D robotics arm. In typical 2D massage chairs, the rollers move up and down; left and right. In a 3D massage chair, the rollers also move in and out creating a much more deep-tissue massage experience. The best chairs in the industry allow you to adjust the rollers intensity and the depth of your massage to your liking. If you're looking for the most life-like experience possible, I would recommend a 3D chair.