Surefire KL3

Surefire KL3, retail $62.00 (
Manufactured by SureFire (
Last updated 04-20-12

The KL3 is Surefire's new Luxeon Star based replacement bezel for your existing Surefire M2 Centurion. Surefire is well-known for making the toughest and brightest personal and tactical lights in the world, and the new KL3 will not disappoint you. (You've read that three times already, haven't you?)
The KL3 will also work with other standard sized 2- and 3-cell Surefire lights, such as the 6P, C2, Z2 and M2. It will run on 6 to 9 volts (2 or 3 CR123A lithium cells.

The beefy, rather mean looking KL3 screws directly onto the body of your existing M2 like the one I was provided with for evaluating the sample. (In this case, I was sent a complete, new in the box Millennium M2 Centurion with all the trimmings plus P60 & P61 lamps! The M2 will be evaluated as a stand-alone product in the near future) The KL3 includes a regulator circuit that assures you a rock-steady output all the way until the batteries expire. I tested the KL3 in the M2 body (2x CR123 cells) and was consistently rewarded with 4.25 to 4.50 hours of fully-regulated light before it began to fall out of regulation and start to dim.


Using the KL3 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 KL3 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. Some models (such as the M2 I tested with) also feature a lock-out tailcap; but otherwise function as above.

The KL3 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 KL3-equipped light the same way you always did: unscrew & remove the KL3 bezel, change the batteries, and screw the KL3 back in place. Be sure the batteries are installed with the button (+) end facing up. You can also tail-feed the KL3-equipped light, but be sure you install the batteries with the button (+) end going in first if you do it this way.

Two battery discharge analyses charts. The first was hand-plotted on-the-fly; the second was fully automated and machine-made using an auto-ranging plotter for less chance of error.

As you can see by the charts, the KL3 remains 100% in regulation for just about 4 1/4 hours, then drops off over the next several hours, ending up in a slow-falling "moon mode" which provides plenty of light for low-level use if you're not in any particular hurry to change the batteries.

The KL3 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.

A Pyrex window protects the "new style" Luxeon Star collimator from scratches and impacts. Just like with the KL1, one thing I noticed as soon as I opened the evaluation sample was just how clean the collimator was. There were no fingerprints or dust on it. Its optics are crystal clear and absolutely spotless. Any dust specks you see in the photos on this page landed there *after* I received the product, not before.

The beam produced by the KL3 is virtually perfect: a bluish-white central hot area that's perfectly centered (virtually impossible given the state of Luxeon Star technology today), fading to a perfectly circular white corona which has a moderately abrupt edge. There is a very faintly visible, thin dark crescent visible near the perimeter, but you really have to be looking for this before you'd ever notice it. Beyond the inner corona lies a much fainter, slightly greenish white outer corona that pretty much fades to nothing a few degrees farther out. As I have nothing to measure beam angles directly, you'll have to wait until I run the KL3 through the beam profile analyzer before exact figures will be known. The beam of the KL3 is just slightly less purplish than the beam of the KL1.

The KL3 is outfitted with a very good regulator circuit. In my tests, it keeps the light output rock steady for well over four hours on a set of two Surefire brand CR123A cells. I would expect similar performance from other brands, given the KL3 does not have an insanely high current drain like an incandescent lamp would. The only real difference between the KL1 and KL3 in this regard is the allowable input voltage range: the KL1 works from 3-9 volts; while the KL3 works from 6-9 volts and only fits the medium (standard) diameter lights like the M2 Centurion. It won't fit the smaller E-series lights, or the larger M3 Combatlight.

Beam photo.
Measured an incredible 370,000mcd at beam center.
Current consumption is only 270 milliamps in a 2-cell light like the M2.

Combat grip
Photograph showing the being used with a gun in a "combat grip".
Note that this is a BB pistol, not a gun that shoots real bullets.
BB gun was used here for representative purposes only.

Spectrographic plot
Spectrographic analysis of the LED (old style) in this flashlight.

Spectrographic plot
Same as above; newer spectrometer software & settings used.

Spectrographic plot
Spectrographic analysis of the LED (new style) in this flashlight.

Spectrographic plot
Same as above; newer spectrometer software & settings used.

Spectrographic plot
Spectrographic analysis of the LED in this flashlight; yet newer spectrometer software settings used.

Spectrographic plot
Spectrographic analysis of the LED in this flashlight; spectrometer's response narrowed to a band between 430nm and 480nm to pinpoint native emission peak wavelength, which is 450.492nm.

USB2000 spectrometer graciously donated by P.L.

ProMetric analysis
Beam cross-sectional analysis; old-style KL3 bezel.

ProMetric analysis
Beam cross-sectional analysis; new-style KL3 bezel.
Images made using the ProMetric System by Radiant Imaging.

Evaluation units were tested in August 2002 just prior to their commercialisation with detailed reports sent to Surefire before this page was constructed. Many thanks to PK at Surefire.

UPDATE: 09-18-02
This page is just now being written, and more data will be added in the coming days. However, I have already tested this product for about one month and have already assigned a final product rating, so you can buy with confidence.

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: 05-09-05
I received a new-style KL3 bezel late this morning. It has a curved Pyrex glass window (or "lens") on the end, is lightly scalloped so you can tell it's still on if it's placed face-down, and it has what I believe is a TIR (total internal reflection) optic behind the lens.

Here is a photograph of the bezel by itself.

And here is a photograph of the front of the new-style KL3 bezel.

Photograph of the new KL3's beam at 12".
Measures 2,410,000mcd on a Meterman LM631 light meter.
Measures 374.0mA in a 2-cell flashlight like the C2 Centurion I used for this test.

Overall, the light has a very, very, VERY slight cyan tint, but it's still white.

Photograph of the new KL3's beam at ~15'.
That red star thing is from an American DJ Laser Widow.

Insanely bright
Excellent construction & engineering
Excellent beam quality
Mean looking cooling fins
Fully regulated with rock-steady light output
Look a lot like the KL1's review? I used it as a template. :)

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: Luxeon Star LED
    No. OF LAMPS: 1
    BEAM TYPE: Circular with central bluish-white hot spot
    SWITCH TYPE: Varies depending on the light you install it in
    BEZEL: Pyrex lens with emitter positioned directly beneath
    BATTERY: 2x or 3x CR123A Lithium Photo Battery
    CURRENT CONSUMPTION: 270mA at 6 volts (same as KL1 on 6v)
    WATER RESISTANT: Yes (when installed on a flashlight)
    SUBMERSIBLE: Yes, to shallow depths at minimum (when installed on a flashlight)
    ACCESSORIES: None that I'm aware of
    WARRANTY: Lifetime


    Star Rating


Do you manufacture or sell an LED flashlight, task light, utility light, or module of some kind? Want to see it tested by a real person, under real working conditions? Do you then want to see how your light did? If you have a sample available for this type of real-world, real-time testing, please contact me at

Please visit this web page for contact information.

Unsolicited flashlights, LEDs, and other products appearing in the mail are welcome, and it will automatically be assumed that you sent it in order to have it tested and evaluated for this site.
Be sure to include contact info or your company website's URL so visitors here will know where to purchase your product.

WHITE 5500-6500K InGaN+phosphor 
ULTRAVIOLET 370-390nm GaN 
BLUE 430nm GaN+SiC
BLUE 450 and 473nm InGaN
BLUE Silicon Carbide
TURQUOISE 495-505nm InGaN
GREEN 525nm InGaN 
YELLOW-GREEN 555-575mn GaAsP & related
YELLOW 585-595nm
AMBER 595-605nm
ORANGE 605-620nm
ORANGISH-RED 620-635nm
RED 640-700nm
INFRARED 700-1300nm
True RGB Full Color LED
Spider (Pirrahna) LEDs
True violet (400-418nm) LEDs
Agilent Barracuda & Prometheus LEDs
Oddball & Miscellaneous LEDs
Programmable RGB LED modules / fixtures
Where to buy these LEDs 
Links to other LED-related websites
The World's First Virtual LED Museum
The Punishment Zone - Where Flashlights Go to Die
Legal horse puckey, etc.
LEDSaurus (on-site LED Mini Mart)

This page is a frame from a website.
If you arrived on this page through an outside link,you can get the "full meal deal" by clicking here.