As the saying goes, it hurts when it is useless, but it doesn't hurt when it is used. So where it hurts, it doesn't work. Knock hard It's best to knock by hand. Just master your own strength. If it hurts too much, it will be smaller, and if it doesn't hurt too much, it will be bigger.
In addition, it is best to knock on the gallbladder in the morning to help promote hair.