ABS-LD-01 Vibra-Infrared Sauna is everywhere, even in people's clenched palms. Infrared - part of the health of sunlight rays. Sunlight is part of a broad spectrum of frequencies, including ultraviolet and infrared. Visible sunlight is in the mid-range of spectral frequencies. At high frequencies, visible light is upgraded to ultraviolet rays that can promote tanning of human skin.