10 Qty. Halco F4 T5 Cool White ProLume F4T5CW 4w Linear Fluorescent Preheat Cool White Lamp Bulb 4 Watts - 4100K Color Temperature Bulb Base : G5 Bulb Shape : F4T5 Linear Fluorescent Average Life (Hours) : 6,000 Length (In.) : 6 - Tube Diameter (In.) : 0.63