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

https://bizzmarkblog.com/is-ultherapy-fda-cleared-for-lifting-or-just-tightening/

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for a deeper lift, with results peaking around 3 to 6 months. In comparison, RF heats tissues to 40-45°C, promoting collagen but with a gentler lift