Low List Price due to limited quantity availability.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.