Ultherapy uses focused ultrasound targeting the 4.5 mm layer beneath the skin...

https://juliet-wiki.win/index.php/Is_There_a_Way_to_Tell_If_a_Clinic_Is_Pushing_One_Device_Only%3F

Ultherapy uses focused ultrasound targeting the 4.5 mm layer beneath the skin called SMAS, which few treatments reach. It triggers collagen buildup over 3 to 6 months for natural lift