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

https://kameronssplendiddigests.zenbloomer.com/posts/does-ultherapy-help-with-skin-texture-or-only-lifting

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for deeper lifting, with results building up to 3 to 6 months. Compared to RF’s surface-level heating around 40 to 45°C, Ultherapy offers more precise depth