1 1/2 in
U-Shaped Lamp,T12 Bulb Shape,2300 lm U-Bend Fluorescent Bulb, Trade Number FB40/T12/CW/6, Bulb Housing Glass, Bulb Shape T12, Color Temperature 4100K, Lumens 2,300 lm, Shatter-Resistant No, Bulb Bend Radius 6 in, Watts 40 W, Bulb Base Type Medium Bi-Pin (G13), Color Rendering Index 90, Dimmable No, Light Technology Fluorescent, Overall Length 22 1/2 in, Voltage 100V AC, ANSI Code 78901-ANSI-4027-1, Standards TCLP Compliant, Bulb Start Type Rapid, Rated Life 18,000 hr, Light Color White, Bulb Dia.