None. Can be costly, plus it may not work (see bottom line). I recently had laser treatment, but I'm not sure which laser I had. I had 2 passes done on my face (I've had scars for 14 years). It hasn't worked, I go back to the clinic in June. From reading this website, the CO2 laser is the best of the 3 lasers available. I've also read that 2-3 passes are needed.