21″ Ply-U-Flex Massage Stick sold with the 4oz Muscle Healing Oil. The massage stick must be used with a lubricant; otherwise, it hurts the skin. The Ply-U-Flex Massage Stick with the Muscle Healing Oil allows you to use enough pressure to open up the muscle tissue to remove fascia adhesions and knots in the muscles. Made from a combination of twelve different Chinese herbs, this oil makes a big difference in muscle health. It penetrates the skin and gives the muscles the nutrition they need to feel good.