* Unique electronic-controlled extremely reliable switch design. * Unique Infinitely Variable Digitally-controlled Brightness System. (100 levels of output!) * Piston Drive (PD) design makes the light more compact than lights with traditional clicky switches. * Switch reliability is greatly increased over traditional switches. * Electronically controlled switching - no spark generated from the piston contact * When the light is off, the microprocessor draws very, very little power - between 0.1-0.4ma (0.2ma typical). For example, one 2000mah cell would last about 416 days! * As with all NiteCore products, they use tough, imported 7075 military-grade aluminum! * Mil-Spec Type III Hard Anodized finish - no bare aluminum exposed, making it more durable. * Resistant to impact from dropping in accordance with US MIL-STD-810F. * Waterproof to IPX-8 standard. * Broad-voltage fully regulated circuit, compatible with standard primary batteries as well as protected li-ion cells * Uses a highly efficient OSRAM Golden Dragon Plus LED lamp. * 130 lumens at maximum output. * Tactical lanyards braided with military-grade 550 parachute-cord. * Uses CR123A's as well as protected lithium-ion RCR123A's! * Stainless steel retaining ring in bezel. * Dimensions: 77mm x 21.5mm or 3.0in x 0.85in (length x diameter) * Weight: 35g or 1.2oz (without batteries) * Runtimes on CR123A (until 50%) Max: 130 lumens, 110 minutes Min: 3 lumens, 65 hours or 2.7 days! * Runtimes on RCR123A (protected only) Max: 130 lumens, 80 minutes Min: 5 lumens, 60 hours or 2.5 days!