Ultherapy uses focused ultrasound to target the 4.5 mm SMAS layer, stimulating...

https://oscar-wiki.win/index.php/Ultherapy_vs_RF_Microneedling:_Which_Is_Better_for_Crepey_Skin%3F

Ultherapy uses focused ultrasound to target the 4.5 mm SMAS layer, stimulating deeper collagen production with results that peak around 3 to 6 months. Unlike RF, which heats skin to 40-45°C for surface tightening, Ultherapy reaches deeper for lifting