Globe 13-Watt Ultra-Mini Compact Fluorescent Spiral Bulb (60-Watt Incandescent Equivalent), Black Light, 3 Pack #37610 A 13W CFL is equivalent to a 60W regular incandescent bulb. It uses less energy, and helps protect the environment. Depending on your kWh rate, you will enjoy significant dollar savings per bulb! An excellent choice for parties, black light bulbs make white objects glow in the dark. Globe's Ultra Mini size fits most fixtures that require a standard medium base regular incandescent bulb. The lifespan of one Globe Enersaver bulb is 8,000 - 10, 000 hours and will outlast 8-10 regular incandescent bulbs. Globe Enersaver bulbs are warranted to last 5 years! If it fails before that time, we will replace it.