The Ultra Sun? MH Conversion Lamp is designed for those who have an existing HPS ballast that want to also be able to run metal halide lamp without purchasing a separate metal halide ballast. With a 6500?K temperature, this lamp is excellent for the vegetative cycle of plants and full term growing. This lamp has been specifically engineered for horticulture applications. Ultra Sun? lamps are high quality, feature robust construction and have excellent reliability at an economical price.