Dermatologists in the U.S. are praising Xerf, a non-invasive radiofrequency device that delivers fast results and minimal pain, as well as the ease of use and effectiveness of the device. The non-invasive device was introduced to the market in Korea by Dr. David Kim, a board-certified dermatologist in New York City, who opened his own practice in the city last month. Xerf uses two radiofrequency wavelengths, each targeting a different layer of the face and allows skin to make new collagen and revitalize itself. The results are immediately noticeable without the need for anesthesia or down time. However, there are still some uncertainties about long-term results and who will have the best outcomes.