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

https://hotel-wiki.win/index.php/Is_There_Downtime_After_a_Thread_Lift_in_Singapore%3F

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer deep under your skin, reaching where threads or RF can’t, for a natural lift. RF heats the skin to 40–45°C, boosting collagen closer to the surface