The PPx uses a patented combination of pneumatic therapy and broadband light to permanently reduce hair. First, the pneumatic suction gently raises the skin into the tip chamber. This action changes the curvature of the skin and brings the hair follicles closer to the surface. Next, a broadband light (much like an IPL) is fired and blanches the skin in the chamber. Finally, the suction is released and the skin falls back into place. Here is a picture showing how the process works:
Because the hair follicles are brought closer to the surface prior to the light being fired, much less energy is required to heat them enough to damage future growth. The lower energy levels also make the treatment completely comfortable. No numbing cream or cooling machines are required.
The main disadvantage of the PPx is that it requires a few more treatments to be as effective as one of the laser technologies.