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

https://www.bookmark-friend.win/ultherapy-uses-focused-ultrasound-to-target-the-4-5-mm-smas-layer-which-few

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for gradual lifting, with peak results in 3 to 6 months. Unlike RF, which heats skin to 40–45°C mainly for tightening, Ultherapy reaches deeper layers