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

https://trulyexpatlifestyle.com/non-surgical-skin-tightening-in-singapore/

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for deep skin lifting, with results peaking around 3 to 6 months. Compared to RF, which heats the skin to 40-45°C mainly for collagen tightening, Ultherapy reaches deeper levels