Square Perfect (4) Pack Professional Quality 100 Watt Compact Fluorescent Full Spectrum 5500K Photo Bulb 5500K day light energy balance spiral energy saver light bulb Optimal color temperature makes this bulb perfect for photography These bulbs are highly rated and recommended by psychologists for SAD (Seasonal Affective Disorder) Approximate Incandescent Equivalent: 300 Watts 100 Watt Fluorescent Full Spectrum Bulb