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

https://johnathanytzx289.image-perth.org/what-does-operator-dependent-mean-for-ultherapy-results

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer for collagen lift, with results peaking around 3 to 6 months