Ultherapy uses ultrasound energy targeting the 4.5 mm SMAS layer deep in the...
https://wiki-wire.win/index.php/Ultherapy_Depth_Settings_%E2%80%93_What_Do_1.5_mm,_3.0_mm,_4.5_mm_Mean%3F
Ultherapy uses ultrasound energy targeting the 4.5 mm SMAS layer deep in the skin, stimulating collagen over 3 to 6 months for gradual lifting. Compared to RF, which heats skin surface to 40-45°C for tightening, Ultherapy reaches deeper layers