Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for deep skin...

https://www.bookmark-tango.win/ultherapy-uses-focused-ultrasound-targeting-the-4-5-mm-smas-layer-to-encourage

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for deep skin lifting, with results peaking around 3 to 6 months. Compared to RF, which heats the skin to 40-45°C mainly for collagen tightening, Ultherapy reaches deeper levels