This DigiLamp 1000W DE PRO+ HPS is among the highest-rated lamp in the market. This commercial-grade lamp packs 155K lumens with a nitrogen-filled quartz arc tube. With a high PAR value of 2100 µmol/s, it’s designed for use in commercial greenhouses to yield sure results and light intensity, while still consuming the same amount of energy as traditional single-ended lamps. The high PAR value provides an efficient photosynthesis reaction due to its increased omission of spectrum red light. *Light Retention – designed to hold 96% of its lumens and PAR after 1 year of usage.