SureFire KL4

SureFire KL4, retail $139.95 (see below) (
Manufactured by SureFire (
Last updated 01-28-09

The KL4 is SureFire's newest Luxeon Star based replacement bezel for your existing SureFire E2 or E2 Executive. SureFire is well-known for making the toughest and brightest personal and tactical lights in the world, and the new KL4 will not disappoint you.

The KL4 uses the new Luxeon Star 5W LED, and uses the SureFire stippled ("orange peel" texture) reflector instead of the acrylic optic that the 1W KL1 and KL3 bezels use.


The sturdy KL4 screws directly onto the body of your existing E2 like the one I was provided with for evaluating the sample. The KL4 includes a regulator circuit that assures you a rock-steady output all the way until the batteries expire.

Using the KL4 is as simple as using any of the other KL series bezels. Unscrew the existing bezel & lamp assembly off your existing light, and screw the KL4 on. It really is just that simple. The switching mechanism will depend on what type and vintage of light you have; but you will always have a choice of momentary operation by pressing the rubber button on the tailcap, or continuous burning by twisting the tailcap in clockwise, or if your light is equipped with a Z57 "clicky" tailcap, by pushing the button a bit more firmly until it clicks. Some models (such as the E2e I tested with) also feature a lock-out tailcap; but otherwise function as above.

The KL4 does not in any way modify your original light, so you are free to switch back to the regular bezel & lamp assembly of your choice any time you wish.

Change the batteries in your KL4-equipped light the same way you always did: unscrew & remove the KL4 bezel, change the batteries (installing the new ones so the positive (+) button end faces forwards, toward the front of the light), and screw the KL4 back in place. Be sure the batteries are installed with the button (+) end facing up toward the KL4 bezel.

I have *not yet* made any battery discharge charts, so that is something that will have to be done in the future. According to another tester, it runs for approximately 80 minutes at full regulation and about 3 hours total on a set of CR123A cells.

The KL4 is extremely well-made and engineered. The same SureFire quality you've come to expect from their personal and tactical lights is built into this product. The finish is a type 3 hard anodize, just like the rest of the SureFire light you installed it on.

One of the things I noticed quickly is that the KL4 has a "scalloped" bezel, so if the light is set face-down while it's burning, some light still escapes and you can easily tell it's still turned on, even if you set it down on a completely flat surface like a tabletop or countertop. No more ruined and wasted batteries from your setting the light down and not realising it's still on.
(Yes, I really did that - to a SureFire KL2 if I remember right!)

The Executive Elite E2e I was provided to test the KL4 on has a Chemcoat treatment inside the barrel (a gold colored material) to help it resist corrosion from water or bad batteries. The flashlight's exterior has fairly aggressive - but not too aggressive knurling (texturising) on the barrel and tailcap. This knurling helps to aid in retention (the ability to hold the flashlight), even if your hands are cold, wet, or oily. In other words, this flashlight is not likely to slip out of your hand unless you purposefully let go of it.

Beam photograph at 12".
Measured an amazing 700,000mcd at beam center.
Current consumption is only 1.00 amps in a 2-cell light like the E2e.
Brownish color is caused by the camera. A more accurate photograph is just below.

Spectrographic plot
Spectrum of the white Luxeon V LED in this flashlight.

ProMetric analysis
Beam cross-sectional analysis.
Image made using the ProMetric System by Radiant Imaging.

Beam photograph onto an almost white wall at approx. 5 feet.

Evaluation unit was provided on June 20 2003. Many thanks to PK at SureFire for providing the test sample.

UPDATE: 06-22-03
Taken from a public message on Candlepower Forums:

"Here's what the Operator's Manual says:
Maximum output of 65 lumens for 65 minutes, followed by 25 minutes of moderate output, with a total "useful" output of over 15 hours. Note: Useful output is defined as a level of output sufficient to illuminate an object, such as a keyhole, from a distance of several inches in total darkness."

(I later confirmed this from the PDF manual itself, which PK kindly emailed me)

I also read that the suggested retail price for the entire L4 flashlight is $139.95.
I don't have independent verification of this, nor do I know how much a KL4 bezel by itself (to be screwed onto an existing E-series flashlight body) costs. Best advice I can offer here is for you to shop around. You'll probably get a better price than MSRP too.

UPDATE: 07-17-03
I've been using this flashlight fairly regularly lately, and found it to be quite handy for most chores requiring a flashlight, even close-up tasks unless of course it's very, very dark and it might be too hard on the 'ol eyeballs to use something this bright in close quarters. For non dark-adapted eyes though, this light is really great to use for whatever you need that requires a flashlight. And it's small and discreet, so it can go pretty much anywhere.

This is available as the SureFire L4 Digital Lumamax (the whole flashlight) if you shop around.
You can also get just the bezel and it fits on any of your SureFire "E" series flashlights.

UPDATE: 04-29-05
SureFire has confirmed that all current SureFire lights should be waterproof to about 33 feet/10 meters. Some evaluations were posted before Surefire made the affirmation that their lights were watertight to 1 atmosphere depth. Any new SureFire lights you purchase now should be considered waterproof to 33' (10M).

UPDATE: 03-16-08
I've been looking for this flashlight for months because I wanted to perform a beam cross-sectional analysis on it, and as you can see, I found it and performed that analysis on it.

Insanely bright.
Excellent construction & engineering.
Excellent beam quality.
Enough spill light to be truly useful.
Fully regulated, burns steady until the batteries poop out.

*Very* slight anodizing color mismatch, however this is normal with the HA-3 process, and will not figure into the rating.

    PRODUCT TYPE: LED Bezel for SureFire lights
    LAMP TYPE: 5W Luxeon Star LED
    No. OF LAMPS: 1
    BEAM TYPE: Circular with central white hot spot and dimmer white corona
    SWITCH TYPE: Varies depending on the light you install it in
    BEZEL: Pyrex lens with stippled reflector & emitter positioned directly beneath
    BATTERY: 2x CR123A Lithium Photo Battery
    CURRENT CONSUMPTION: 1.00 amps at 6 volts
    WATER RESISTANT: Yes (when installed on a flashlight)
    SUBMERSIBLE: Yes, to 33 feet (when installed on a flashlight)
    ACCESSORIES: None that I'm aware of
    WARRANTY: Lifetime


    Star Rating


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