1000W Sun Pulse Metal Halide Grow lamps are specially formulated for plants and other living things. These lamps are available in Kelvin ratings of 3k, 4k, 6.4k, & 10k. Full spectrum and specialized spectrum lamps allow you to mix and match to create perfect mixtures for your specific applications. These lamps have also been designed to work with electronic and digital ballasts. They won't destroy electronic ballast or be destroyed themselves. These pulse start lamps were created to withstand the 4khz pulse that electronic ballasts use to ignite lamps,(this is what destroys standard MH lamps) only HPS grow lamps can handle this type of ignition process. Because our new Sun Pulse lamps are designed to withstand 4-6 kHz pulses, you will experience long and even lamp life approx (20,000 hrs) with little color shift or loss of FT-CD output. Special Features: Won't Damage Electronic or Digital Ballast Elliptical shaped arc tube for better distribution of light Long Lamp life Low color shift .