Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer to lift and...

https://ace-wiki.win/index.php/Ultherapy_Depth_Settings_%E2%80%93_What_Do_1.5_mm,_3.0_mm,_4.5_mm_Mean%3F

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer to lift and tighten deeper tissue, with results peaking around 3 to 6 months. Compared to RF that heats skin to 40-45°C for surface tightening, Ultherapy reaches deeper layers