The Streamlight Survivor comes equipped with a C4® LED which is shock-proof with a 50,000 hour lifetime. The unbreakable polycarbonate lens with a silicone anti-scratch coating is assembled in a heavy-duty bezel with a sealed o-ring. This light has 4 modes: High: 36,000 Candela peak beam intensity, 140 lumens, 4 hour runtime. Low: 12,000 Candela peak beam intensity, 47 Lumens, 15 hour runtime. Flash: 8 hour runtime. Moonlight: 20 day runtime. The moonlight mode is a very low mode that will literally run for days. To enable to this feature simply turn the light on and then hold the switch down through the high, low, and strobe settings, after 6 to 8 seconds it will go into the moonlight mode. The deep-dish parabolic reflector produces a narrow beam; ideal for cutting through smoke or fog. It also has optimum peripheral illumination to aid in navigation. The industrial rechargeable nickel-cadmium 4.8 volt, 1.8 amp hour, 4 cell sub-C can be recharged up to 1,000 times. An optional four "AA" alkaline non-rechargeable battery pack provides fast replacement with readily available batteries. The Survivor has a sonic welded push button switch designed for extremely long life. A rubber dome push button actuator provides easy operation even when wearing heavy gloves.