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

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

Ultherapy uses focused ultrasound energy to target the 4.5 mm SMAS layer deep under the skin, promoting gradual lifting over 3 to 6 months. Compared to RF heating skin to 40 to 45°C for collagen boost, Ultherapy reaches deeper layers