Beware of other sellers offering TheraBulb products that may be counterfeit or used. 120V for Use in US, Canada, Mexico, and other countries with 120V electrical systems. Not for use in Africa, Asia, Europe, Oceania, or other countries with 240V electrical systems. High Intensity Incandescent 300 Watt Near Infrared Red Light Bulbs. Includes One Pair of 3.0 IR, ANSI/ISEA Z87.1+ Compliant Red Light Filtering Glasses. Includes One Paperback Copy of Infrared Light Therapy for Recovery, Fitness, Skin Care, and Total-Body Wellness. Bulb Infrared Output Verified by Independent Laboratory. Bulbs Are Lab-Certified Not to Emit EMF. Bulbs Fit Standard US Socket E26 Rated at 300 Watts or Higher. Bulbs Are Size R40: 6.5 Inches High by 5.25 Inches in Diameter. Bulbs Are Compatible with Infrared Saunas Using Incandescent Infrared Light Bulbs. This is a near infrared/ red light/ heat bulb. It is not a decorator bulb. Double reflective red coat. May show minor cosmetic blemishes on the surface of the bulb including. Small dimples, bubbles, small spots of darker or lighter color, small marks on bulb, or color variation. These conditions may be more apparent when the bulb is on, but are unrelated to the wavelengths that are produced by the bulb and do not negatively impact its performance. All near infrared, red light, and heat output is produced by the filament that is inside the bulb.