G E LIGHTING 42732 T9 Circular Bulb, 20W, Cool White It is GE FC6T9/CW 20W T9 Cool White Circular Bulb Tube Is Over 1" In Diameter 6" Diameter Spacing Inside Tube 4 Pin Base Rated Life: 12 000 Hours Lumen: 800 Color Temperature: 4100 Kelvin CRI: 60 Boxed