A lighting assembly that incorporates a high brightness LED in a compact assembly that is sealed and sufficiently durable for a continuous operational range of between 350 feet below sea level and 35,000 feet above sea level. Further, the flashlight of the present invention includes a novel modular interface arrangement that allows the flashlight to be interfaced with a variety of different equipment or reconfigured in order to facilitate use for different functionality such as a marker light, a runway indicator light or a weapon mounted light.