Picosecond Laser Pen Light Therapy Tattoo Scar Mole Freckle Removal Dark Spot Remover Machine Skin Care Beauty Device NeatcellFunctions: What is difference between Blue light picosecond pen and Red light picosecond 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