Designed and engineered for the horticulture industry, Genesis HPS Bulbs maintains less lumen and PAR depreciation over standard bulbs on the market. They can be mounted in vertical and horizontal lighting fixtures and is compatable with newer digital e-ballasts or classic magnetic coil ballasts. The HPS Bulb delivers 27% more energy in the blue and red enhanced ARC spectrum and secures up to 19% more total spectral energy over leading competitor brands. Spectral enhancements increase your plant's photosynthetic response and increased PAR output generates more vigorous flowerings sets and bud sites. All Genesis Bulbs use Pulse Start Technology. Available in 400 Watt, 600 Watt, and 1000 Watt.