The wavelength infrared puts out is longer than the wavelength of red light, which allows infrared to penetrate more deeply into the body. Thus, the reason infrared provides some similar, but some completely different benefits than red light. Red light is visible and is most effective for use on the surface of the skin. Red light occupies the “long end” of the visible spectrum with wavelengths of 630nm-700nm. Infrared light is invisible and is effective for use on the surface of the skin as well as penetration of about 1.5 inches into the body. Infrared sits right next to red light on the electromagnetic spectrum at 800nm to 1millimeter.