UFO 2 and UFO 3 have the same function, but they differ in a few ways. Firstly, the LED therapy on UFO 3 has two modes (constant and pulsating), while UFO 2 does not have this alternative. Also, UFO 3 has 22 pre-programmed treatments, which are 8 additional preset treatments on the device that UFO 2 does not have. And finally, UFO 3 has app reminders, while UFO 2 does not.