Exilis has both Ultrasound and Radiofrequency energy, deployed as a widespread, diffuse heating, which causes the skin to contract and build new collagen. Ultherapy deploys focused ultrasound energy in little spots of controlled heating - this can be targeted in both depth and specific areas. Ultherapy is less comfortable than Exilis Ultra (which is why we offer pronox for Ultherapy and Exillis feels like a hot stone massage, so no numbing is needed). Both work by triggering the body to build new collagen, and both have no downtime. Exilis tends to be less expensive, but you will need multiple treatments with Exilis in a series, whereas most people do just 1 treatment of Ultherapy.