10 Qty. Halco F13 T5 Cool White ProLume F13T5CW 13w Linear Fluorescent Preheat Cool White Lamp Bulb 13 Watts - 4100K Color Temperature Bulb Base : G5 Bulb Shape : F13T5 Linear Fluorescent Average Life (Hours) : 6,000 Length (In.) : 21 - Tube Diameter (In.) : 0.63