Lamp manufacturers have pursued the ideal spectral output for plant growth for years. The biggest advancements made in HID sources for plant growth has been to enhance the inherent deficiencies of either H.P.S. or M.H. While these specialized lamps are much better than standard lamps, the fact is that neither technology can be altered enough to be truly optimum for plant growth. The Ushio Dual is the finest H.I.D. lamp that combines both enhanced M.H. and Super H.P.S. technologies to achieve strong peaks for both vegetative growth and flowering. Must be run in 1000w H.P.S. System.