This model BS-LHR9 diode laser is targeting at the purpose of hair removing based on the light and heat theory. The pigment in the hair follicle absorbs the laser light and converts the light to heat. The heat, in turn, damages the follicle and destroys its ability to re-grow. It is important to treat each follicle during the growth cycle for maximum hair reduction. The laser pulses for just a fraction of a second, heating the hair follicle and impairing its ability to re-grow. Significantly less hair grows back with each treatment and ultimately resulting in your goal of permanent hair reduction. The number of treatments required varies from individual to individual. The diode laser light is in the advantage of its wavelength, and suitable for most kinds of skin type and color for hair removing. Due to the longer wavelength provides deeper and safer penetration into the skin than other kinds of light based hair removal, it benefits the patients with deep color skin. (Except certain part of body for black color skin people) The tiny size brings high mobility to this equipment, and it is also suitable for small clinics or even home .