F4T5/CW Mini. Fluorescent Bulb 6 in 4 W Bi-Pin Cool White (4 pack) 4 watt cool white, Mini Bi-Pin T5 base, 120 volt, Lumen: 135, CRI: 62, Temperature: 4100k, Long life: 6,000, Length: 6 inches, Diameter: 5/8 inch, UL Listed