... Principle It is uesd Bi-polar Radio Frequency ( RF ) energy. It produce heat tissues's electrical resistance ... -injection, non-narcosis, shortening hairdressing time;Intelligent cooling system makes non wound treatment, stimulating long time collagen rebirth ... mode- continue /pulse makes thorough treatment . Portable RF Skin Rejuvenation system, skin-tigntening,crinkles removal,tiredness alleviation