- The wave length of the rays is classified as infrared rays, visible rays, ultraviolet rays and   X-rays in order from the longest. Ultraviolet rays are utilized mainly to the dermatological   treatment as its length too long to penetrate into the skin. As a kind of wave energy, the   frequency ranges of infrared rays in 0.76~1.5 microns are called near infrared rays, 1.5~5.6   micron rays are medium infrared rays and 5.6~1.000 microns far infrared rays. A German   physicist(The Nobel Prize Winner) proved that infrared rays with the frequency ranges   between 6~14 micron are effective to ionized heat treatment. - Deodorizing harmless to human body - Lead to sound sleep - Absorbing and dispersing of electromagnetic waves - Promotion of blood circulation - Neutralizing effects of poison - Insecticidal effects