Ultherapy uses focused ultrasound to target the 4.5 mm SMAS layer, making it...

https://www.hometalk.com/member/254051008/alice1337254

Ultherapy uses focused ultrasound to target the 4.5 mm SMAS layer, making it stand out for deeper tightening compared to radiofrequency’s surface-level heating of around 40 to 45°C. Standard HIFU often works at a shallower depth