Prometheus Brass Beta QRv2 Review

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The original Prometheus Beta-QR was a massive Kickstarter success. Nearly 2,000 backers pledged to see a new take on the keychain light, and Jason Hui of Prometheus Lights launched the Beta to an eager market. While I wasn’t able to jump on the original v1 release, I couldn’t resist his collaboration with Scout Leather Co. on a brass Beta, now sporting an upgraded, sleeker version of the quick-release mechanism. Before receiving the light, I was convinced that the Beta was the perfect AAA flashlight. After a few months of carrying the Beta-QRv2, here are my thoughts.

The Specs

Body length (with QR tail): 3.45 in.

Body length (without QR tail): 2.95 in.

Material: Solid brass

Emitter: Nichia 219 High CRI LED

Brightness levels: 1 / 15 / 85 lm

Runtime at each level: 55h / 4h / 45m

Design, Fit, and Finish

I’ve seen and used a lot of keychain flashlights, from Photon button LEDs to the Victorinox SAK lights to AAA titanium lights like the Fenix E99Ti which have a great balance of size, power, and runtime. While each have their strengths in different areas, I haven’t yet seen a production light that comes close to the fit and finish of the Beta. Despite being mass-produced at a specialist flashlight factory in China, Jason’s supervision and the factory’s sole production focus shines through in the light.

The Beta adopts Prometheus’s design language of clean lines and signature body ribbing, manufactured to a tolerance that rivals the best custom lights, as the usual suspects of mass production are noticeably absent. Its Nichia 219 emitter is perfectly centered. The notches on the head where they meet the opening’s chamfer are smooth with no machined artifacts. The body ridges are smooth and spaced to catch your fingers just right no matter your grip preference. The quick-release mechanism sits completely flush with no perceptible play when attached to the light, but the Beta comes with an extra QR tail machined by Jason himself to be 100% within spec. I don’t think the threads could be any smoother, and that’s coming from someone who dislikes twisty activation to begin with.

Months later, I still find it hard to believe that this light is mass-produced. The solid brass construction also does nothing but favors for the Beta, putting it in the upper echelons of exclusivity and desirability usually reserved for full-custom lights.

Performance and Operation

The Beta’s silky-smooth threads make operating it a delight. As mentioned earlier I’m not a big fan of twisty activation, but every time this light is in my hands I can’t help but fiddle with it and twist out a few cycles of its modes. The length of its head — while a drawback for its portability — makes it possible to do one-handed activation, but given how smooth and shallow its head grooves are, the action is not as natural as it could be.

Its three modes are nicely spaced. Its low setting of 1 lumen is enough for navigating in the dark without ruining your night vision or waking up your family members, and its high setting of 85 lumens is more than capable for most tasks. Irrespective of brightness, however, is the quality of its Nichia 219 emitter.

Every flashlight enthusiast owes it to themselves to own an N219 light. Akin to an afternoon sun, its color rendering index (CRI) of 90+ is currently the highest in the industry; comparatively, most cool white emitters can only do under 70. This means that the Beta gives off a more natural and “real world” quality when used, which is very pleasing to the eyes. Seeing tint of this quality will make it hard to go back to regular cool white lights — I’ve bought nothing but warm/neutral tint lights since owning the Beta.

The Beta’s unique selling proposition, of course, is the quick-release mechanism on its tail. Specially constructed out of canted-coil springs, it can take up to 10 pounds of force before release. Plenty of force for retention during normal carry, but also easy to snap on and off when required. If the N219 emitter is my primary reason for purchasing this light, then the QR is definitely the second.

No other flashlight has a feature like this, full-sized or otherwise, and based on the dozens of products that have come and are coming out to improve key and keychain management, it’s a welcome feature that makes the Beta very handy to carry despite its size. I found myself reaching for it first even when I had a larger light clipped to the same pocket.

Carry Options

I said “despite its size” in the last section with good reason. The Beta’s length is slightly prohibitive, adding about an inch to the length of its chambered AAA cell. If you have shallow pockets, you may have difficulty making room for the Beta, especially with a longer belt suspension tool like its partner the Scout Hook.

With that said, the weight from the solid brass it uses makes it less “bouncy” when suspended externally, and also plays into the usefulness of its quick-release system. I’ve also tried carrying it on my hip loop or towards the rear so it sits flush in my back pocket, but I think its ideal location is still on the front where it can be conveniently disengaged.

Prometheus Lights also manufactures a titanium clip for use with the Beta, slotting right into its quick-release port and providing a deep pocket carry. If dangling isn’t your thing, this is a good alternative, but be warned that the clip won’t come off without a fight after its installation.

Pros and Cons


  • Mass-produced availability but custom-level fit and finish
  • Best flashlight tint on the market
  • Quick-release mechanism performs as advertised
  • Many carry options


  • Expensive compared to its peers
  • Weight isn’t for someone looking for a light that disappears on a keychain
  • Slightly too long


Owning and using the Beta has definitely changed my outlook on keychain lights and flashlights as a whole. After I got my fill of “pocket rockets” and got to experience the Beta’s premium brass and tint, I’m convinced that the bar has been set for production lights. Flashlight companies take note: this is how to properly do a midtech light that can compete with both mass production and custom jobs.

While I no longer think it’s the absolute perfect AAA/keychain light due to its size and price, I think it comes pretty close, and currently has no competition against its unique features.

You don’t have to spend hundreds of dollars to see what the fuss is about with custom lights — with the Beta, you can experience the same materials and tint from the best of them. It’s not the ideal light for every EDC, but it’s one that will enrich all of them.

BUY ($80)

Disclaimer: I purchased my Beta-QR unit myself for personal use as part of the Kickstarter campaign and was not provided a review unit by either Prometheus Lights or Scout Leather Co.

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