Compact fluorescent spiral bulbs provide the light you need while reducing energy costs. These work great in our Dayspot grow light and fixture. 26 watt/6400K bulb is equivalent to a 130W incandescent bulb. Produces 1600 lumens and will last an average of 10,000 hours. Fits any light fixture. Medium Base. UL LISTED. Rated 6400 kelvin rating.