The Ultra Sun? Dual Arc Tube Lamp offers the best of both worlds with a 600 watt HPS and a 400 watt MH arc tube both inside one lamp jacket, operating simultaneously. This full spectrum lamp has a 3,000?K color temperature achieved by the dual arc tubes working together. This lamp is an excellent choice for full term growth, flowering and fruiting. The Dual Arc Tube lamp operates on a standard 1000 watt HPS magnetic ballast or an electronic ballast such as the Galaxy? brand. These lamps have been specifically engineered for horticulture applications. Ultra Sun? lamps are high quality, feature robust construction and have excellent reliability at an economical price.