... Frequency Machine,RF Skin Tightening MachineTheory of Monopolar RF MachineMonopolar RF takes that epidermis balances normal temperature, RF electric waveproduces ... on assurement of skincomfortable, harmless, it uses RF electric wave to produce heat exchange, precisely attainsskin deep, stimulates ... layer.When deep collagentissue is heated up to 45°C-60°C, it will naturally produce instant shrinking, ...