Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for deeper...
https://wiki-stock.win/index.php/Why_Is_Imaging_Such_a_Big_Deal_in_Ultrasound_Skin_Tightening%3F
Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for deeper lifting, with results peaking around 3 to 6 months. RF heats skin between 40 to 45°C to boost collagen, great for surface tightening but less depth