Omega PRO-PAR SERIES 400w SUPER HPS Son-T (Flowering) Lamp Colour temperature: 2000k Lifetime: 24,000 hrs E40 Fitting SUPER HPS Lamps have the highest Orange / Red Spectrum than any other HPS Lamp. Giving you the best results during the Flowering Stage of your plants. Although HPS Son-T Lamps can be used throughout the vegetative and flowering stages, for optimum results I recommend using a Metal Halide Lamp for the vegetative stage PRO-PAR SERIES, SUPER LUMEN TECHNOLOGY 10% more light than a standard HPS lamp. This extremely energy-efficient plant grow lamp provides more energy which is essential for optimized photosynthetic response. Long life, economical. Omega Pro-Par HPS Lamps are High Pressure Sodium lamps designed to deliver 10% more light than standard HPS lamps. PLEASE NOTE: All (HPS) High Pressure Sodium and (MH) Metal Halide Lamps require a Ballast to power them. Please do not purchase unless you fully understand this. If you need any further information, please just let me know.