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

https://shed-wiki.win/index.php/Why_Does_My_Jawline_Look_Softer_Even_If_My_Skin_Texture_Is_Fine%3F

Ultherapy uses focused ultrasound energy to target the deeper 4.5 mm SMAS layer, stimulating collagen over 3 to 6 months for gradual lifting. Compared to RF, which heats skin to 40-45°C mainly in the superficial layers, Ultherapy reaches deeper tissue