6 Qty. Halco F20 T12 Daylight ProLume F20T12DL 20w Linear Fluorescent Preheat Daylight Lamp Bulb 20 Watts - 6500K Color Temperature Bulb Base : G13 Bulb Shape : F20T12 Linear Fluorescent Average Life (Hours) : 8,000 Length (In.) : 24 - Tube Diameter (In.) : 1.5