2 Pack 13 Watt Black Light (Blue) Spiral Lamp Compact Fluorescent 2 pack of 13 watt spiral lamp black(blue), 120 volts with a medium(edison) screw base. Electronic ballast provides instant on, no flicker. Low mercury. Not for use on dimming circuits, timers or remotes. UL approved and CUL listed. 75% energy savings compared to a 60 watt bulb. 10,000 hrs. average rated life. Small size easily replaces standard incandescent light bulbs.