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

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

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for gradual lifting, with peak results in 3 to 6 months. Unlike RF, which heats skin to 40–45°C mainly for tightening, Ultherapy reaches deeper layers