rf machine for face lift chin lift tender skin striae ... skin surface into the subcutaneous tissue. With the high frequency of 450 kHz, the electric field changes ... same frequency. Then the subcutaneous natural resistance produces heat through the movement. Which makes the dermal collagen ... Building 3,No.3,Xijing Road,Badachu High-Tech Zone, Shijingshan District, Beijing, ChinaMobile:0086-13718331363