Triangle Bulbs T30031-10 - F13T5/WW, 13 Watt, T5, 3000K Warm White, 21" Straight Fluorescent Tube Light Bulb, 10-Pack Pack of 10 bulbs F13T5/WW, 13-Watt T5 21" Maximum Overall lenght DOUBLE EXTRA LONG LIFE - 20,000 HOURS Warm White, 3000K