This HPSgrow lamp allows you to stretch yourgrowing seasonto 365 days a year. Fine-tune your lighting system toprovide optimumspectral energy level that promotes vigorous plantgrowth. HPS growlamps provide up to 10% more available energyfor plantgrowth than that of standard high pressure sodiumlamps. HPS growlamp's enhanced spectral energy distributionis designedto grow a wider variety of plants.