Nowadays, household appliances are more and more advanced, and the electromagnetic waves emitted by them are also "invisible killers" that endanger people's health. However, scientists have found through research that certain frequencies of electromagnetic waves can promote people's health, and now there are some special instruments that use electromagnetic waves as a treatment. For example, when people have burns or joint sprains, they can use electromagnetic therapy for physical therapy; There is also electromagnetic therapy for beauty slimming and so on. However, the cost of this treatment is not low, and the effect is not obvious if you don't insist on it.