Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer deep under...

https://griffinphut760.theglensecret.com/what-is-the-submental-area-and-which-treatment-targets-it

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer deep under your skin, reaching where threads or RF can’t, for a natural lift. RF heats the skin to 40–45°C, boosting collagen closer to the surface