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

https://www.pure-bookmark.win/ultherapy-targets-the-deep-4-5-mm-smas-layer-with-ultrasound-to-lift-and

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