4 Watt (40w Replacement) Led Light Bulb with Built-in Anion Air Purifier Ionizer Negative Ion Generator, Cool White 40W Incandescent bulb replacement; High performance LED lighting coupled with air purification through the production of anions (negative ions) Purifies air from: cooking odors, cigarette smoke, airborne bacteria, pet dander, dust mites, pollutants, etc. Provides many health benefits such as relieve asthma & allergies, strengthen immunity, and increase metabolism Life: 50,000 hours = about 22.8 years (Based on 6 hrs/day) Energy efficient: saves up to 90% less electricity than incandescent bulbs; Estimated Yearly Energy Cost: $ 0.74 (Based on 6 hrs/day, 8.5 c/kWh. Costs depend on rates and use)