Luxrite 20178 13-watt 120-volt Ultra Super Mini Twist 4100K Fluorescent Bulb, Cool White Fluorescent bulbs are energy saving bulbs and last up to 10 times longer than incandescent bulbs Fluorescent bulbs help you save money using 40 - 70% less energy than incandescent bulbs Fluorescent bulbs are 5-8 times more brighter (more output lumens /watt) than incandescent bulbs Luxrite Mini Twist fluorescent bulb, 13W, Base: E26 Medium Screw, Color Temp: 4100K, Rated Life (hours): 10000