Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer, stimulating...

https://messiahwmff829.lucialpiazzale.com/what-is-the-submental-area-and-which-treatment-targets-it

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer, stimulating collagen deep under your skin for a natural lift. Compared to RF, which heats the surface around 40 to 45°C, Ultherapy penetrates deeper