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

https://www.acid-bookmarks.win/ultherapy-uses-focused-ultrasound-to-target-the-4-5-mm-smas-layer-beneath-your

Ultherapy uses focused ultrasound at 4.5 mm to target the SMAS layer, stimulating collagen deep within for natural lift over 3 to 6 months. Compared to RF, which heats skin at 40-45°C mainly for surface tightening, Ultherapy reaches deeper layers