Working theory The life-span and health of human are determined by the amount of electrons found in the body. A healthy person should contain 80% negative electrons and 20% positive electrons. If fact, we are living in a world contaminated with harmful substances in air, water, seas, lakes and rivers, forests, soil erosion, reduction in farming land, depletion of ozone layer, global warming, electromagnetism radiation, rapid growth of cities and roads etc. these factors threaten our health by affecting the existing magnetic field in our bodies, which are crucial elements in human body. When the electrons on the outer of our body encounter physicals reaction in the atmosphere, they will be released form the nuclear, and become positive charged ions after losing the gas molecule in the electron itself. It happens in the same way when our bodies will become tired when we lose large amount of anions and maintaining large amount of cation. The accumulation of excessive cation will be become toxins in our bodies. Crystal ion cleanse foot spa can enhance the natural healing power and immunity system, normalize the function of natural healing power (elimination of external objects) , nervous system (rectifying the nerve) and endocrine system (regulate and normalize hormones) . Reactivating the entire body, helps eliminates illness, restoring smooth and youthful skin. Besides from strengthening the body, enhancing health and long-lived, crystal ion cleanse foot spa is capable of preventing scores of diseases. Mode options: 4 modes are available, since this is merely a normal health protection, mode 1, 2, 3 are recommended. 1) 70 + (positive electricity) / 30- (negative electricity) this setting is suitable for all, even without going through muscle test. (weaker) . 2) 15 + (positive electricity) / 10- (negative electricity) / 5 + (positive electricity) (medium) 3) 10- (negative electricity) / 15 + (positive electricity) / 5- (negative electricity) (stronger) 4) 50 + (positive electricity) / 50- (negative electricity) / only for new electrodes (first time)