The SureFire X300U-B Handgun Weaponlight is a popular choice among law enforcement and military personnel around the world. Using SureFire's own TIR lens, the X300U-A produces a powerful 1000 beam of blinding white light, generated through a recoil-proof LED emitter. The X300U-B is highly effective at close to medium range engagements with the beam's large center spot and peripheral illumination for constant situational awareness. This system is perfect for positively illuminating/identifying threats while simultaneously impairing your target's vision temporarily. In addition, the X300U-B has two modes, momentary-on and constant-on. Momentary-on is activated by pressing and holding down the ambidextrous tail-cap toggle switches, keeping the light activated until released. Constant-on is activated by quickly pressing and releasing the toggle switch, this will keep the light active until switched off. Features of the X300U-B Handgun Weaponlight:1000 lumen outputMomentary-on and Constant-on modes1.25 hour runtime213 meter illumination distance SureFire X300U-B Ultra 1000 LU Tan Handgun WeaponLight w/ Thumb Screw Mount X300U-B-TN