Ultherapy uses focused ultrasound to target the deep 4.5 mm SMAS layer,...

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

Ultherapy uses focused ultrasound to target the deep 4.5 mm SMAS layer, encouraging natural collagen over 3 to 6 months for gradual lifting. Compared to RF, which heats skin surface to around 40-45°C, it's deeper but less immediate