he StenLight S7 is a high powered LED lamp designed especially for the hostile caving environment. Mud, water, and shock-resistant, the S7 was designed by cavers to address the shortcomings of conventional cave lamps. Key Features: Brightest portable LED light available Extremely long LED life (>20,000 hours) Solid state and shock-resistant – no breakable filament or gas-filled tubes Flicker-free all-analog control circuit provides current regulation at all brightness levels for constant brightness Operates off any 6 to 18 volt DC power source High electrical and optical efficiency make the most of your batteries (96% electrical efficiency from 7.2V, 93% from 12V) Compact, rugged anodized aluminum case Lightweight -- under 125 grams Long throw, high durability magnetic switch Water-resistant up to 25 feet (no moving parts penetrate the sealed lamp body) Smooth, optimized beam pattern with user-swappable lens options Temperature limiting to prevent overheating of LEDs or exterior Four logarithmic brightness levels Swivel bracket supports easy adjustment of a wide range of vertical angles The StenLight S7 uses a high-efficiency all-analog control circuit that regulates LED current in all brightness modes, and limits itself to a safe temperature by reducing LED current when necessary. The magnetically controlled switch has 5 clearly-defined positions that are separated to avoid accidentally switching the unit off. The switch has no moving parts inside the lamp body, and is fail-safe – if the switch is destroyed or the magnet lost, the unit defaults to the LOW setting, which is still bright enough for you to find your way.