Ultherapy uses ultrasound energy targeting the 4.5 mm SMAS layer deep in the...

https://www.lima-bookmarkings.win/ultherapy-uses-focused-ultrasound-to-reach-the-4-5-mm-smas-layer-which

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