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Quark QK16L MKIII - Midnight Blue

$85.00 $95.00
New for 2023: Midnight Blue with 90+ CRI Nichia 319A.

Nothing lasts this long without being the best. The first Quark was launched in 2009. We don't release a new light every 5 minutes, because we spent the last 14 years making this one better.

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Quark QK16L MKIII - Midnight Blue
Quark QK16L MKIII - Midnight Blue Quark QK16L MKIII - Midnight Blue Quark QK16L MKIII - Midnight Blue Quark QK16L MKIII - Midnight Blue Quark QK16L MKIII - Midnight Blue Quark QK16L MKIII - Midnight Blue Quark QK16L MKIII - Midnight Blue Quark QK16L MKIII - Midnight Blue
Product Overview


Nichia 319A



1.5 hrs

160 hrs

4000K @ 90+

The classic Quark, modernized: It was a huge responsibility to take something so good and improve upon it, but that’s just what we’ve done. When I took over the Foursevens brand from David in 2018, this Quark project quickly became all-consuming. How to take my 10 years of experience designing high-end custom flashlights and combine them with the decade David spent reiterating and refining the brand’s flagship? The end result is the Quark MKIII, the best Quark yet, and I’m thrilled to have the opportunity to get one into your hands.

Product Details

The Quark was the first commercially produced "high output" LED flashlight on the market. When the Quark flashlight hit the scene some 10 years ago, it completely shattered the mold and ushered in the era of modern EDC (Every Day Carry) flashlights. It put the Foursevens brand (and founder David Chow) on the map as an innovation leader in the world of EDC gear and spawned a new flashlight form factor that other manufacturers were quick to imitate.

Since then, the Quark has continuously evolved and the MKIII is intended to continue that legacy. I like to think the Quark is the Porsche 911 of flashlights: some things are so good they don’t need to be re-invented, they just need to be refined.

BATTERY WARNING: The QUARK QK16L MKIII will accept 2xCR123 or 2xRCR123 batteries. However, we STRONGLY ADVISE AGAINST THEIR USE. Catastrophic failure can occur when one of the two cells is not functioning correctly, causing thermal runaway in the other cell. There is a significant risk of fire and/or explosion when using two cells.

Burst mode
Using a very fast double press, burst mode (100%) output is directly accessible from any previous level, and reverts to the last saved mode. Experts agree that most flashlights are used at lower level outputs, but sometimes you need to dial it to up. We've got you covered on both counts.
Hybrid Memory
A blend of memory and no-memory, the hybrid configuration saves the last mode used, but reverts to the first mode in the sequence when shifting out of a saved mode.
pocket friendly
I eliminated grooves or knurling under the pocket clip to ensure your light won't destroy your pants pocket, while maintaining the secure hold and smooth engagement you expect from my pocket clips.
Solid Copper (Direct Thermal) MCPCB
Pioneered by custom makers and modders, the LED is mounted to a solid copper PCB to provide superior thermal performance and maximum output. A first for the Quark.
digital bump protection
Exclusive to Prometheus and Foursevens, Digital Bump Protection prevents accidental mode changes if the light is dropped or tapped on a surface when tail standing. The software detects very short power interruptions and ignores them. Other lights will think you've requested a mode change.
DIY Friendly
*warning-nerd content* This industry was created by individual makers and modders working at home on their kitchen tables. People who love tinkering, technology, and flashlights! Unlike most industries, flashlights have been driven by the little guys and we intend to honor that tradition. Most manufacturers (including Foursevens in the past) glue or thread lock on certain components so they cannot be disassembled without a lot of effort and/or destroying the light. This was to prevent people from tinkering. I say tinker on my friends!
Included with your Quark
  • Quark QK16L Flashlight
  • Foursevens 16650 battery
  • Tailstand Cap
  • 2 Spare O-rings
  • Instruction Manual

Operating your Quark is simple:

  • Make sure that the battery is inserted with the positive side (+) toward the head.
  • To turn it on press or click the tailcap button. A press allows momentary activation of the light.
  • A quick off/on cycle changes modes
  • Two very quick off/on cycles activates burst mode
  • Enter configuration mode with 10 on/off cycles in less than 3 seconds: The light will begin to blink a number of times corresponding to the selected configuration. For example if you are in Config. 3: 3 blinks, pause, 3 blinks. If there is no input for 5 seconds the light will exit configuration mode.
  • Turn the light off for 5 seconds to save the current configuration to memory

All Quarks are initially set to Configuration 3 with Medium/High/Burst. They can be reconfigured as often as you'd like.

Here are the possible configurations:

  • Config. 1: High - (Burst 100%)
  • Config. 2: Max (100%) - Strobe
  • Config. 3: Medium - High - (Burst)
  • Config. 4: Low - Medium - High - (Burst)
  • Config. 5: High - Medium - Low - (Burst)
  • Config. 6: Low - Med - High - Strobe - SOS - Beacon - (Burst)

Brightness Levels

  • Low (Moonlight): 0.8 lumens, 160 hrs
  • Medium: 70 lumens, 16 hrs
  • High 350 lumens 1.75 hrs
  • Max/Burst 650 lumens, 1.5 hrs (30 seconds burst, then steps down to high)
  • LED Type
    Nichia 319A (4000K / 90+ CRI)
  • battery type
    Foursevens 16650 battery (2200mAh - 4.4A - protected Li-Ion)
  • Weight
    3.2 oz (with battery)
  • Dimensions
    Length: 4.5" / Diameter: 0.88"
  • Voltage Range
  • Beam Distance
  • Body Materials
    Type-III hard-anodized 6061-T6 aluminum
  • Window Glass
    Optical grade glass (2 side AR coated)
  • Water Resistance
    IPX8 (1m)
  • Where it's Made
Industry-leading LED
The Slate Blue MKIII features the newest Nichia 319A with 4000K color temperature and 90+ CRI. It's meant to strike the perfect balance between beam quality and output.
Industry-leading LED
Configurable interface
No one can agree on the best program setup so we offer 6 convenient program presets (configurations). Choose your favorite, at any time. The configurable interface is standardized across the entire Foursevens line. No matter what light you pick up, you'll know exactly how to use it.
Configurable interface
The best pocket clips on the market
Pocket clips are my jam because I obsess about every detail, because every detail matters. The new clip is made from thicker material, provides easier pocketing, and improved grip. Most of the "grip" on a flashlight comes from the pocket clip, not the surface finish.
The best pocket clips on the market
tailstand cap
(if you know, you know.): The Tailstand Cap is designed to be backwards compatible with all Quarks ever made. All Quarks ship with the traditional forward (momentary) clicky switch that stands proud of the tail. For those who prefer a recessed button and a light that can tailstand, we also include the all new snap-on Quark Tailstand Cap.
tailstand cap
Customer Reviews
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