Grow Green Double-Ended High Pressure Sodium (HPS) Lamp,1000WGROW GREEN lamps emit light in the right spectrum, they are highly efficient and their low sensitivity to interference and long service life set them apart from other alternatives. And the result is a better harvest. Ideal for cultivation with high light demands High proportions of red and blue light guarantee efficient photosynthesis Highest output of PAR light (2100 mol s) promotes photosynthesis Lots of red light for more photosynthesis and good