Heavy CO² Laser: A carbon dioxide (CO²) laser beam uses intense, precisely-focused light which vaporizes the surface skin and reveals the undamaged layer beneath. Active FX is a procedure using fractional laser resurfacing. Fractional coverage means that only a fraction of the surface of our skin is actually treated by the laser. By leaving small “bridges” of untouched skin, you heal much quicker and you can get back to your busy lifestyle sooner. So the greatest benefit to the Active FX is noticeable results with little downtime.