The ABI near infrared LED light bulb emits the most powerful therapeutic near infrared wavelength of 850nm. Near infrared light is invisible to the naked eye. When using this bulb, you can feel the light's warmth and you can measure it's power, but you will not be able to see it. 50,000+ hour service life 3-year manufacturer's warranty Assembled in the USA Fits a standard household E26 socket 100-240V AC input LEDs: 18pcs 850nm Near Infrared Nominal Rating: 54W (18x3W) Class Power Draw: 27W Beam Angle: 60-degree Internal cooling fan Irradiance: 92.4 mW/cm² (6' distance); 47.6 mW/cm² (12' distance) Energy per 5 minutes: 27.7 joules/cm² (6' distance); 14.3 joules/cm² (12' distance)