This machine is great if you position it on certain places. It has like balls or something in it that are very hard and they can hurt if it hits the wrong spot so uncertain places it feels good, but if it hits the wrong spot, it hurts so I give it a three star because it helps but then it鈥檚 also very aggressive and you鈥檙e unable to adjust the balls?.? if they were silicone and not rocks would be better