Ultherapy targets the deeper 4.5 mm SMAS layer using focused ultrasound,...

https://technivorz.com/why-is-imaging-such-a-big-deal-in-ultrasound-skin-tightening/

Ultherapy targets the deeper 4.5 mm SMAS layer using focused ultrasound, promoting gradual tightening over 3 to 6 months. Compared to RF, which heats skin to 40-45°C mainly for surface collagen, Ultherapy reaches deeper layers