Satco S4372 13W Triple Tube 4-Pin GX24Q-1 Plug-In base 4100K fluorescent bulb 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 Sylvania T4 fluorescent bulb, 13W, Base: GX24Q-1, Color Temp: 4100K, Rated Life (hours): 12000