100 watt replacement using only 23 watts (for almost as much light - 1640 lumens vs. 1690 lumens). This 2pk will save $184 in energy costs (Each bulb saves $92 in energy cost over the average rated life (12,000 hours) of the lamp compared to a 100 watt (1000 hours) incandescent bulb. Total package energy savings based on 2 bulbs X $92 energy savings/bulb. Based on 10 cents/kWh.). To save energy costs, find the bulb with the light output you need, then choose the one with the lowest watts. Light output: 1640 lumens. Energy used: 23 watts. Life: 12,000 hours. Now smaller than ever. Lasts 11 years! Light output. As an Energy Star Partner, Osram Sylvania has determined that this product meets the Energy Star guidelines for energy efficiency. Light output has more than 5% decrease when lamp is used in base down position. Lamps operated in recessed or enclosed fixtures will have reduced lamp life. Note: Reliable operating temperature range 0 degrees F/-18 degrees C to 100 degrees F/40 degrees C. Color temperature is 2700K. This bulb uses only 23 watts and is 1640 lumens bright. UL listed. Made in China.