The L4 is equipped with a new click-on/click-off tailcap pushbutton switch that gives the user the tactical advantage of momentary activation or the convenience of a constant-on switch in a single switch. The L4 also features digital current regulation circuitry to match the LED's current requirements with the battery's output to maintain a more consistent level of light output for the useable life of the batteries (as opposed to unregulated lights, which are subject to a steady decline in light intensity beginning shortly after activation).

Constructed of aerospace grade aluminum with a rugged military specification hard-anodized finish, and powered by two lithium batteries (10-year shelf life), the L4 LumaMax features a five-watt LED (Light Emitting Diode) and the extended runtime typical of LED flashlights. With a maximum light output of 100 lumens, the L4 is the first LED flashlight bright enough to qualify for tactical use.

The L4 produces 100 lumens of light for over an hour, followed by lower output for over two hours. Unlike most LED flashlight manufacturers -- who inflate the light output and usable runtimes of their LEDs -- SureFire provides realistic output and runtime specifications based on scientifically obtained measurements. Although any LED -- including those produced by SureFire -- can continue to produce negligible light output for over 100 hours, the amount of useful light produced is of a shorter duration.