Surefire M640U Scoutlight Pro LED Weapon Light, Aluminum, Includes 2 CR123A Batteries

The Surefire M640U Scoutlight Pro LED weapon light is a 1000-lumen tactical light purpose-built for rifle and carbine platforms where versatility, durability, and real-world performance matter. Whether you're training on the range, running low-light drills, or gearing up for field work, this compact aluminum light delivers the output and beam characteristics serious shooters depend on.

Built around a high-output LED and a proprietary TIR lens, the M640U shapes its beam to strike the balance between reach and peripheral illumination—useful whether you're working indoors at close quarters or scanning terrain at medium distance. The light runs for approximately 1.25 hours on the two included CR123A batteries, giving you substantial runtime for typical training and deployment scenarios. The aerospace-grade aluminum body is hard-anodized to mil-spec standards and sealed with O-rings, so it can handle the recoil impulse of centerfire rifles and the weather it collects along the way without degrading.

The standout feature here is Surefire's Low-Profile Mount (LPM), which lets you dial in exactly where the light sits on your rail system. Instead of forcing your light into a fixed position that may conflict with other mounted gear, the LPM gives you the freedom to optimize placement relative to your scope, sight, or other accessories. The mount works on any MIL-STD-1913 Picatinny or M-LOK equipped forend or handguard. Activation is intuitive: a protected push-button tailcap switch for intuitive cycling between momentary and constant-on modes. That simplicity under stress is what separates tools from gadgets.

If you run a modern rifle platform and want a compact, proven light that doesn't sacrifice output or user control, the M640U earns its place in your kit.

Key Features

• 1000 lumens of tactical-grade output from an ultra-high-output LED
• Proprietary TIR lens balances long-range reach with usable surround light
• Low-Profile Mount (LPM) allows optimized positioning on the rail without interference from other accessories
• Compatible with MIL-STD-1913 Picatinny and M-LOK rail systems
• Momentary and constant-on switching via protected push-button tailcap
• Lightweight aerospace aluminum construction with mil-spec hard-anodized finish
• O-ring sealed against weather and elements
• Runs approximately 1.25 hours on two CR123A batteries (included)
• Includes mounting hardware for both rail standards

Specifications

Frequently Asked Questions

Will the M640U work with my AR-15 or carbine handguard?

Yes. The M640U mounts to any forend or handguard equipped with MIL-STD-1913 Picatinny slots or M-LOK attachment points. The Low-Profile Mount and included hardware cover both standards, so setup is straightforward regardless of your rail type.

Can I use the M640U with a scope or other rail-mounted gear?

Absolutely. The Low-Profile Mount is designed to let you position the light where it won't interfere with your scope, red dot, or other accessories. The versatility of the LPM is one of its main strengths—you can dial in the exact placement that works for your setup.

How long do the batteries last?

The M640U produces tactical-level light for approximately 1.25 hours on two CR123A batteries. The two batteries needed to run the light are included with the unit, so you're ready to train or deploy right out of the box.

Is the M640U sealed against rain and dust?

Yes. The body is constructed of aerospace-grade aluminum with a mil-spec hard-anodized finish and is O-ring sealed, which keeps weather and the elements out of the internals. It's built to handle field conditions and the recoil impulse of centerfire rifles without degradation.