This TCP compact fluorescent energy efficient light bulb is as bright as a 150 watt incandescent bulb, but uses only 42 watts of electricity. Its spiral compact fluorescent design fits anywhere a regular incandescent bulb fits. The 10,000 hour average bulb life is approximately the lifetime of 13 incandescent bulbs, saving you time and effort as well as money. TCP's unique lead-free glass and a specialized phosphor mix keep light output high over the lifetime of the bulb. This bulb is not suitable for use on dimming circuits. This bulb is ideal for use in Bare Bulb Fixtures, Ceiling Fixtures, Floor and Table Lamps, Wall Sconces and Outdoor Lamps. 5100 Kelvin Color temperature approximates mid-day sunlight.