This bulb must be operated in a high pressure sodium ballastSun Pulse Pulse Start Metal Halide Grow lamps were created by the GAS Technologies group of photo-biologists, plant scientists, mechanical and electrical engineers, gas chemists, and HID lamp designers. They are designed with true solar symmetry for true photochemical reactions in living organisms, greater molecular efficiency in operations, and better color rendering. Sun Pulse lamps are made with the highest quality and quality control.