1,Quick effect 2,No side effects 3,portable&beautiful 4,easy and simple to handle 5, ... elasticity and brightness, and finally bring the effect of skin whitening,fixing,rejuvenation and ante-oxidantApplicable ... . Yellow Light: ( 590nm):The yellow light is for skin whitening and skin tender as well ... safety3. No hurt to the skin cell, no side effect4. Simple operation, no need of professional training5. ...