Ultherapy targets the 4.5 mm SMAS layer with focused ultrasound, reaching...

https://xeon-wiki.win/index.php/How_Do_Doctors_Decide_Ultherapy_Energy_Level_and_Depth%3F

Ultherapy targets the 4.5 mm SMAS layer with focused ultrasound, reaching deeper than standard HIFU, which usually treats up to 3 mm. RF heats skin to about 40-45°C for collagen boost but stays more superficial