7 colors LED Photon Electric Derma Pen 

The Derma pen is automatic and rechargeable, It is easy to use, you don`t have to buy a new
one every time, Just replace the needle. Needle length is adjustable to different sizes depending on the areas and purposes of the treatment. It is more convenient to treat narrow areas such as the nose, around the eye or mouth. 
 

What is it for hot selling 7 color led light pen? 

The biological tissue of the human body can absorb light and convert which can lead to a series of chemical
reactions-photodecomposition, photo-oxidation, photopolymerization, photosensitization. Different wavelength has different functions. The light can be absorbed by cell chondriosome and lead to an enzymatic reaction