6 Pack of Rough Service Light Bulbs A-19 Brass Base at 120 volts, 550 lumens of light, 66 watts, 10,000 hours at 130 volts, 725 lumens of light, 75 watts, 5,000 hours Supreme Lighting, SLI Made in USA Features A variety of wattages from 4 Watt night lights to 500 Watt industrial bulbs A range of finishes including Clear, Frosted, Soft White, and Protected. (See the Toughcoat/Teflon coated section of our website for these products) Different life ratings - many products are offered in 5,000, 10,000, and 20,000 hour life ratings. These are designed for applications where the labor cost to change lamps is very high and lower light output is acceptable A broad range of heat lamps Compatible with most dimming operations