3 Functions with Quick Click access. Momentary - Full Power - Strobe In developing the MAG-TAC® LED flashlight, we aimed to produce an advanced lighting tool that, in appearance, build quality and performance, would rival tactical flashlights costing several times more. The result is the first Mag® flashlight to use extreme-performance lithium CR123 batteries – a rugged, fast-handling, "fist-grabbable" flashlight that achieves truly stunning performance for its size. Thanks to a tailcap switch, it turns on and off without changing the beam's focal setting. Designed with extensive input from military tactical consultants, and yet suitable also for civilian use, this crowned-bezel version of the MAG-TAC® LED flashlight comes with a detachable pocket clip and features three modes: Momentary (in which the light stays on only while the switch button is being pressed); Full Power for a dazzling, 320-lumen beam that can light up an object two football fields away; and Strobe for a high-energy 12 Hz strobe that can disorient an opponent. All functions are selectable through Mag Instrument's tailcap-switch-activated "Quick-Click™" mode selector. Specifications: Length: 5.275 (133.98 mm) Barrel Diameter: 1.050 (26.67 mm) Head Diameter: 1.050 (26.67 mm) Weight with batteries: 4.8 oz. (136 g) Batteries Required: (2) CR123 batteries (included) * Per ANSI/NEMA FL-1 Standard.