The Surefire L5 features ultra-bright, five-watt LED for performance, click-on/off switch for convenience. Whether you're flying an F/A-18, assaulting a beachhead, or simply walking the dog, the L5 LumaMax won't let you down when the going gets tough. Powered by two lithium batteries (10-year shelf life), the L5 is equipped with an ultra-bright, 5-watt LED that produces a maximum output of approximately 65 lumens (more powerful than typical four D-cell alkaline flashlight) and over 3 hours of total useful light. CNC machined from aerospace-grade aluminum and coated in a military specification Type III hard-anodized finish, the L5 utilizes an ergonomic flat-side Grip design and a patented rubber grip ring. The L5 features a new click-on/off tailcap pushbutton switch that gives the user the tactical advantage of momentary activation or the convenience of a constant-on 'click' switch in a single switch. The L5 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).