Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for a natural...

https://landensnewperspective.hexaforgey.com/posts/what-does-mfu-v-stand-for-in-ultherapy-a-clear-guide-to-understanding-the-technology-behind-the-lift

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for a natural lift that builds over 3 to 6 months. Compared to RF’s surface heating at 40 to 45°C, it reaches deeper for firmer results