The Ultra Sun™ MH Conversion Lamps are designed for those who have an existing HPS ballast that want to also be able to run metal halide lamps without purchasing a separate metal halide ballast. With a 6500°K temperature, these lamps are excellent for the vegetative cycle of plants and full term growing. 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. One year warranty.