Two primary manufacturers produce bulbs suitable for the demands of Halcyon underwater lights. Welch Allyn is a very large manufacturer, producing a range of medical devices including HID lighting. Historically, these bulbs were superior to any competitive products. Approximately five years ago, Halcyon was one of the very first to receive samples from an auto parts company (Bright Star) forging into underwater lighting technology. These initial samples showed promise but were inferior in terms of reliability as well as the quality of light output. However, Halcyon remained in communication with Bright Star, continuously evaluating the newest iterations of their HID components. After five years of continual improvement, we are confident that Bright Star represents the best value in the 21-watt segment of the Halcyon product line. Our 10-watt HID lighting is still produced by Welch Allyn and we continue working with both companies while evaluating ongoing technology innovations.