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

https://bizzmarkblog.com/is-ultherapy-fda-cleared-for-lifting-or-just-tightening/

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