Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great at breaking up those knots

If you suffer from tight shoulders and upper back then this cane is a must for you! You can choose how much pressure to apply and the cane itself is indestructable. My Chiropractor actually tried to break it and ended up pulling a muscle and then had to use the cane to relieve the tightness in the muscle. The instruction booklet is great and there are many different areas of the body you can use it on but I typically use it for my upper back and shoulders and sometimes my neck. Co-workers ususally point and laugh and ask me how much I paid for my "car club" until they try it. As a result four of my friends have bought one too. Well worth the price and it will last you a lifetime.