The Arc6 is the latest product by specialty flashlight manufacturer Arc Flashlight, designed and produced by Peter Gransee. Some consider these Arc Flashlights a custom products, and are not available in commercial stores. Right up the front is a crenellated titanium bezel, the bezel is somewhat thinner than most others but still does its job of protecting the front end. This thinner bezel also means that it's less obtrusive too. The shallow crenellations allow for light to shine through when placed on flat surfaces. The bezel can be easily unscrewed by hand, without the need of any special tools. This is an intentional design by the manufacturer as it allows for easy access to the components within the head such as lens, LED and electronics. This allows for future upgrading instead of having to buy an entire new light. A thick silicone o-ring sits between the bezel and AR coated sapphire lens, sufficiently tightening the bezel will ensure a good seal at the front end. The Arc6 uses a textured aluminum reflector with a consistent fine texture and is well-polished with no noticeable flaws. Sitting at the bottom of the reflector cup is the LED which is just slightly misaligned, though it doesn't affect the beam profile at all. On its exterior, the head has machined flutes running all around. In addition to providing an aesthetic touch, they also provides excellent grip when twisting the head for constant activation. The threads are of average thickness, smoothly cut and are coated in Type 3 anodizing, as with the other parts of the light, and comes pre-lubricated with a thick grease-like substance. It deserves to be mentioned that the anodizing on the Arc6 is one of, if not the most durable I've seen on any light. From the rear you can see part of the PCB, along with the "+" battery contact and the kilroy switch mechanism.

The overall size of the Arc6 depends on which sleeve/battery tube you choose. Either types are available for purchase separately if you wish to have both. Both these sleeves have identical piston drive switching mechanism on the inside. This piston drive means that there isn't an actual switch in the tail end, instead this piston slides within the sleeve when depressed from the rear, activating the switching mechanism in the head of the light. This is theoretically more efficient and durable than a regular switch module, but it doesn't provide the same tactile feedback as a regular switch. At the rear end on the piston is a small rounded edges rectangle slot which is meant for tritium vials to be placed in. The spring used in the Arc6 is very stiff, an intentional design choice by the manufacturer to make it more durable, and gives switch presses a firmer feel. The stiff push button might not suite everyone, but at least you won't have to worry about the piston not rebounded back as some users have experienced with the NiteCore PD series. Now let's take a look at the differences between the two sleeves. First the Guarded Sleeve, its rear end extends beyond the piston switch which prevents accidental activation and also lets the light stand on its tail end on flat surfaces. It also comes with a removable titanium clip, however the alignment of the clip is a little too far back and makes the light wobble slightly when standing on its tail. The clip itself works well and provides a very tight grip, you should take additional care when clipping it on thin fabrics. The No Guarded sleeve, has the piston stick protruding out the rear end. This allows the light to be activated more easily. There is no clip and also fewer ribs machined along the sleeve as compared to the Guarded Sleeve. While the Type 3 anodizing is consistent throughout the Guarded Sleeve, the No Guarded Sleeve has some slight areas of varying shades towards the rear end as can be seen in the image gallery below. This is obviously a very subtle cosmetic issue which doesn't affect the usage of the light at all, but still noted as some users can be particular about anodizing color consistency.

If you're unfamiliar with any of the terms used in this review, click here for explanations on common flashlight related vocabulary.

The Arc6 uses an Z-Power P4 LED, and along with its textured reflector, produces a very smooth beam profile. There is no clearly defined hotspot or spill area, instead, the hotspot transitions gradually towards the spill. No beam artifacts are present, and beam color is a nice neutral white, for the most part. On the brightest level there is tint shift which causes the beam to turn noticeably blue as can be seen with the control shots on level 7.

The Arc6 is a programmable light which allows the user to select from 7 brightness levels and strobe, which can be set to any of the 2 switch/stage positions. The first stage is activated when the piston makes contact with the kilroy mechanism. This can be done either by twisting the sleeve for constant activation, or by partially depressing the piston for momentary activation. The second stage is activate by fully tightening the sleeve for constant activation, or fully depressing the piston for momentary activation. The activation of stage 1 and 2 is similar to how the SureFire L1 switches between high and low levels. Do take note that there is a third virtual stage in addition to the 2 mechanical stages. This virtual stage is activated when the switching transitions from off to the second stage in less than 0.5 seconds. The virtual stage can also be programmed, just like the other stages. A good setting for the virtual stage would be a relatively bright level or strobe, something which you may need in an emergency situation.

While the Arc6 does a great job of distributing heat from the LED, it's still a rather small body and as such has built-in thermal protection which prevents the light from getting to hot, primarily meant to protect users from burning themselves. Once triggered, it causes the output to drop to Level 3 brightness for the remainder of the battery like. Of course you are not stuck at this level, simply switch off the light letting it cool down and the light will turn on at the higher levels again. While the protection kicks in during most of my runtime tests, it didn't trigger when I ran the Arc6 at Level 7 on a 16340 cell for some reason as can be seen from the runtime graph below.

Update October 08, 2008
According to Peter of Arc Flashlight, some Arc6's may exhibit tint shift either to yellow or blue at the higher levels, however it will stabilize in about a minute. Arc Flashlight can also replace it under warranty.

The Good - Great construction quality, excellent and very durable anodizing. Mates form and function well. Smooth beam profile. Relatively simple programming technique.

The Bad - LED is over-driven at Level 7 causing tint shift. Output drops very quickly on levels 5 through 7 due to thermal protection, and overall short runtime relative to output intensity.

The Relative - Neutral white tint on most levels. Stiff springs result in stiff momentary activation mechanism. Able to tail stand with Guarded Sleeve. Functions as both momentary activation by push button, and constant activation by twist action. Allows for modular component upgrades in the future.

Head (front view).

Head (side view).

Head (rear view).

No Guarded Sleeve (front view).

No Guarded Sleeve (side view).

No Guarded Sleeve (rear view).

Guarded Sleeve (front view).

Guarded Sleeve (side view).

Guarded Sleeve (rear view).