Ultherapy in Singapore uses focused ultrasound targeting the 4.5 mm SMAS layer...

https://www.bookmarkingvictor.win/ultherapy-uses-focused-ultrasound-to-target-the-4-5-mm-smas-layer-deep-under-1

Ultherapy in Singapore uses focused ultrasound targeting the 4.5 mm SMAS layer to lift and tighten skin gradually, with results peaking around 3 to 6 months