CFL bulb uses 75 percent less energy and lasts eight times longer than a regular incandescent bulb. T5 spiral design provides clean, beautiful light in any room to save money on energy without sacrificing style. 55-watt bulb is designed to last up to 8,000 hours at 3,800 lumens. Color temperature is measured at 2,700 Kelvin. Medium screw base is designed for table lamps, floor lamps and more.