Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for a firm...
https://www.blaze-bookmarks.win/ultherapy-uses-focused-ultrasound-targeting-the-4-5-mm-smas-layer-for-gradual
Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for a firm lift, with results peaking around 3 to 6 months