... Frequency Machine,RF Skin Tightening MachineTheory of Monopolar RF MachineMonopolar RF takes that epidermis balances normal temperature, RF electric waveproduces ... based on assurement of skincomfortable, harmless, it uses RF electric wave to produce heat exchange, precisely attainsskin ... different sizes of RF heads, suitable for faceskin or body different parts.4. Safety switch: it controls emergency ...