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

https://ace-wiki.win/index.php/Secret_RF_vs_Thermage:_What_Is_the_Real_Difference%3F

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for deep skin tightening, with results peaking around 3 to 6 months. RF heats the skin at 40 to 45°C to boost collagen more superficially and often requires multiple sessions