Function: 1. Tattoo removal(Only work on black color tattoo) 2. Mole removal 3. Dark Spot/ Freckle/ Pigment removal Advice: red pen continuous output mode to remove tattoo blue pen to remove spot, mole and freckle and ect. The Difference between Blue And Red Light Pen The power and effect of blue light picosecond pen is more stronger, it need more professionl operation, you have to wear the goggles when you use the blue one. You have to press the switch button when you use the blue pen, while you don't have to for the red pen. The blue laser pen has 9 output mode, different output frequency and wavelength. The red laser pen has 3 output mode, continuous output, Interval 1-3 seconds output and Interval 5-7 seconds output