Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer to tighten...

https://front-wiki.win/index.php/What_Does_MFU-V_Stand_For_in_Ultherapy%3F_A_Clear_Guide_to_Understanding_the_Technology_Behind_the_Lift

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer to tighten skin deeper than RF and standard HIFU, which mostly warm surface layers around 40 to 45°C