The SureFire HL1 Helmet Light is a compact, lightweight, watertight, multiple-output unit that can be attached to military PASGT and TC 2000 Modular Integrated Communications (MICH) helmets, as well as caving, climbing, construction, and search-and-rescue-helmets. The Helmet Light uses a single 123A lithium battery, three separate switches, and six light-emitting diodes (LED's) to produce three different types of light at multiple power levels: HL1-A-TN