I use these bulbs myself and they work great! Much more efficient than other types of grow bulbs. They only use 26w of electricity but put out over 1600 lumens. They come in 6500k for vegetativegrowth, or 2700k for flowering. Compare my prices to any other on ebay. Same quality, Great price! Please specify the color temp you want or try them both for excellent results. For every thing you need to know about growing with CFLs check out the website below.