Bulb Type: FC18T5 Bulb Category: Fluorescent Bulb Style: Circline (round) Color Temperature: Full SpectrumCorrelated Color Temperature (CCT): 5,500KBulb Brightness: 1,100 Lumens Color Rendering Index (CRI): 91 Pin Base: 4-pin (G10q) Tube Diameter: 0.625" (15.87mm) Bulb Diameter: 5.5" (139.70mm) Average Bulb Life: 12,000 Hours