Philips 315W CMH lamps are used in all of the Maxibright 315W CM Lighting Kits and are also used in some other grow lights from companies such as Dimlux. They are pretty much the industry standard 315W CMH, or CDM, lamps for growing plants. Other 315W CMH/CDM lamps are available but emit quite different spectrums, they are not as effective for plant growth. A flowering specific lamp Promotes strong structural growth and rampant flowering Increases taste and aroma in most flowering plants Should be used as a total source of light for flowering plants for best results Fuller light spectrum than the 942 Daylight version