These SunBlaster CFL self ballasted lamps are excellent for a variety of indoor growing applications. Use these affordable lamps anywhere you need to replicate the sun's natural light. Easy to use, the 13, 26 and 55 Watt lamps simply screw into any standard size light socket. The 125 Watt and 200 Watt lamps require a mogul socket. The 6400K spectrum of these lamps is ideal for propagation and continued growth of most indoor plants."