Vacuum cupping therapy is the use of mechanical principle of extraction, makes the formation of negative pressure inside the tank, tank adsorption in selected areas (points or focal point), make the skin and shallow muscle hyperemia, stimulate human body skin, tendons, meridian acupoints to remove toxins, dredge meridian, qi and activating blood, centralizer thrift and regulate viscera function such as a kind of drug therapy. Note: product not sent box, if need to box please add $5 Thank you very much