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

https://www.generate-bookmark.win/ultherapy-uses-focused-ultrasound-targeting-the-4-5-mm-smas-layer-to-tighten

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