Virtual Sun VS400HPS 400-Watt HPS Grow Light Blub High power 400-watts (hps) bulb - 50,000 lumens high output - color temperature: 2,100k Average life span 20,000 to 24,000 hours Hps bulb give out 10% more light than standard bulb - 10% increase of light output = 10 % more plant growth 30% more blue/violet provides better range for your plant Fits all standard 400 watts hps grow light systems