Description
SureFire X300U-B WeaponLight at a Glance
The SureFire X300U-B is a rail-mounted weapon light built around a single high-output LED behind a precision TIR lens, an aluminum T-slot mount and an ambidextrous push and toggle switch. One figure needs checking before purchase: the specification below quotes 600 lumens, while other listings for X300U variants quote 1,000 lumens. SureFire has sold the X300 Ultra family at more than one output level, so confirm the rating against the manufacturer sheet for the exact part number rather than relying on marketplace copy. Buyers comparing rail-mounted options across the tactical flashlight and weapon light category will find the same discrepancy repeated in several places.
Manufacturer Specifications
- Special off-white high-performance LED produces 600 lumens, biased in the yellowish-green spectrum optimal for human vision
- Precision TIR lens creates a smooth, tight beam with enough surround light for peripheral illumination
- Switching-Ambidextrous push/toggle, integral, ergonomic one-finger ambidextrous momentary – and constant -on switching
- Integral aluminum T-slot mounting system offers rock-solid attachment to railed hand guns and long guns equipped with MIL-STD 1913 rails
- Construction: High-strength aerospace aluminum with Mil-Spec anodizing; coated, tempered window
- NOTE: Refer the User Manual before use. Bezel diameter: 1.125 inches
Reading the Specification
Three items on that list do most of the work. The TIR lens determines the beam shape, producing a defined centre with usable spill rather than a single hot spot, which is what makes a light usable for identification at indoor distances. The T-slot mount fixes the light to MIL-STD 1913 rails on either a pistol or a long gun, which is why the same body appears in both roles. The aerospace aluminum body with Mil-Spec anodizing and a coated, tempered window is the durability specification, and it is the main reason this line is priced above most competitors. Note that no runtime figure and no IP rating appear in the listing data; both are worth confirming, since primary-cell weapon lights in this class typically publish around an hour at full output.
The switch is integral rather than remote. For a long gun where the light sits forward on a handguard, users generally add a separate tape switch such as the SureFire DS00 switch assembly, which is a component rather than a complete light. The equivalent dedicated long-gun body in the same family is the SureFire Scout Light Pro with the low-profile M-LOK and 1913 mount.
Where It Sits Against Alternatives
In the pistol-light segment the usual comparisons are smaller and cheaper. The Streamlight TLR-6 HL is built for compact pistol frames and trades output for a much smaller footprint, while the Nightstick TCM-10 ships with five modular rail inserts to cover a wider range of rail geometries than a single T-slot fitting. The SureFire’s case rests on the body specification and the beam optic rather than on features per dollar, and the missing runtime and sealing figures should be resolved before comparing prices directly.
