Wurkkos WK03 Flashlight Review

Wurkkos WK03 Flashlight Review

The Wurkkos WK03 is a low-cost 18650-based flashlight that offers USB-C charging and a nice range of output! It makes a great gift!

Official Specs and Features

Here’s a link to the Wurkkos WK03 flashlight product page.


There’s only one version of the Wurkkos WK03 flashlight but it’s available with or without the 18650 seen in this review.


The Wurkkos WK03 flashlight sells for the remarkable price of $14.99 or $16.99 with cell. Buy the cell package! 

Short Review

I can’t even imagine how they make this light for such a low cost. It’s a nice one, too! The build quality is good and charging works great. A complete package USB-C charging flashlight for under $17 just seems crazy! 

Long Review

The Big Table

Wurkkos WK03 Flashlight
Emitter: Luminus SST-40
Price in USD at publication time: $14.99
Cell: 1×18650
Turbo Runtime Graph
LVP? Yes
Switch Type: E-Switch
Quiescent Current (mA): 0.01
On-Board Charging? Yes
Charge Port Type: USB-C
Charge Graph
Power off Charge Port With or without cell or tailcap: one mode (medium)
Claimed Lumens (lm) 1800
Measured Lumens (at 30s) 1366 (75.9% of claim)^
Candela per Lumen 11.6
Claimed Throw (m) 217
Candela (Calculated) in cd (at 30s) 531lux @ 5.357m = 15238cd
Throw (Calculated) (m) 246.9 (113.8% of claim)^
Claimed CCT
Measured CCT Range (K) 6000-6600 Kelvin
Item provided for review by: Wurkkos
All my Wurkkos reviews!

^ Measurement disclaimer:  I am an amateur flashlight reviewer.  I don’t have $10,000 or even $1,000 worth of testing equipment.  I test output and such in PVC tubes!!  Please consider claims within 10% of what I measure to be perfectly reasonable (accurate, even).

What’s Included

Wurkkos WK03 flashlight what's included

  • Wurkkos WK03 flashlight
  • Wurkkos 3000mAh 18650
  • Charging cable (USB to USB-C)
  • Lanyard
  • Spare o-rings (2)
  • Manual, etc.

Package and Manual

Wurkkos WK03 flashlight box

Wurkkos WK03 flashlight box

Wurkkos WK03 flashlight manual

Wurkkos WK03 flashlight manual

Wurkkos WK03 flashlight manual


Build Quality and Disassembly

Wurkkos WK03 flashlight

The build quality is great! This light punches WAY above $15.

Wurkkos WK03 flashlight tailcap

Wurkkos WK03 flashlight cooling fins

Wurkkos WK03 flashlight tailcap spring

Wurkkos WK03 flashlight head spring

In case you’re wondering, or maybe in case you’ve picked up on it already… Yes this Wurkkos WK03 and the Sofirn SC18 are nearly identical! Same specifications, same nearly everything, in fact. This Wurkkos has knurling though, while the Sofirn SC18 has ridges – which one you decide to purchase may come down to a preference between those two design features! (See photo comparison below.)

Size and Comps

Dimension: 101.5mm (length) × 24.7mm (head diameter)
Weight: 55g (without battery)

If the flashlight will headstand, I’ll show it here (usually the third photo).  If the flashlight will tailstand, I’ll show that here, too (usually the fourth photo).

Wurkkos WK03 flashlight in hand

Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

Also above is the light beside my custom engraved TorchLAB BOSS 35, an 18350 light.  I reviewed the aluminum version of that light in both 35 and 70 formats.

Here’s the Sofirn SC18 flashlight alongside a Wurkkos WK03. You might notice that they have similar designs! Performance is basically the same, too. Basically, the difference is that one has knurling (WK03) and one has ridges (SC18). I reviewed the SC18 already.

Retention and Carry

There’s a friction-fit pocket clip included for carrying the Wurkkos WK03 flashlight. 

Wurkkos WK03 flashlight pocket clip

This is a pretty simple pocket clip but does attach securely and ships already attached.

Clip hug!

Wurkkos WK03 flashlight pocket clip hug

Next up for carry is the included lanyard. This lanyard attaches through a hole in the tailcap.

Wurkkos WK03 flashlight lanyard hole

There’s just one hole and this prevents clean tailstanding when the lanyard is in use. 

Wurkkos WK03 flashlight lanyard

No magnet or anything else is included.

Power and Runtime

The Wurkkos WK03 flashlight operates on a single lithium-ion cell.  I have a package that had a cell included.  It’s a 3000mAh button top and is a completely standard cell.

Wurkkos WK03 flashlight with included 18650

The cell goes into the light in the “usual way” (which is to say that the positive terminal of the cell goes into the light).  

Wurkkos WK03 flashlight with included 18650 installed

Unlike on the Sofirn SC18, there’s no silk-screened logo to indicate the battery direction (this is fine for me.)

Here are a number of runtime tests.

runtime graphs

runtime graphs

runtime graphs

runtime graphs
Low voltage protection is observed in all tests.


The Wurkkos WK03 flashlight also has built-in charging, by way of a USB-C port on the head. 

Wurkkos WK03 flashlight charging cable

Charging works great and only takes around 2.25 hours to complete.

charging graph

C to C charging even works great, too! Again, for $15….

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Turbo 1800 2.3h 1366 4.02
High 800 2.6h 681 1.61
Medium 350 6.3h 292 0.67
Low 100 23h 73 0.22
Moon 3 230h 2.8 12.4mA

Pulse Width Modulation

Every mode uses PWM. It’s fairly fast PWM and I can’t say I noticed it during use.

For reference, here’s a baseline shot, with all the room lights off and almost nothing hitting the sensor.  Also, here’s the light with the worst PWM I could find.  I’m adding multiple timescales, so it’ll be easier to compare to the test light.  Unfortunately, the PWM on this light is so bad that it doesn’t even work with my normal scale, with is 50 microseconds (50us).  10ms5ms2ms1ms0.5ms0.2ms.  In a display faster than 0.2ms or so, the on/off cycle is more than one screen, so it’d just (very incorrectly) look like a flat line.  I wrote more about this Ultrafire WF-602C flashlight and explained a little about PWM too.

User Interface and Operation

Control of the Wurkkos WK03 flashlight is performed through a single e-switch. This is a soft switch and has an indication function in the center.w

Wurkkos WK03 flashlight e-switch

Wurkkos WK03 flashlight e-switch profile

Wurkkos WK03 flashlight e-switch actuation

The switch can indicate in green and red and flashing. When the Wurkkos WK03 flashlight is turned on, the switch will indicate the approximate battery level for around 5 seconds. Green means “good” and red means “poor” (or “low”). Flashing red means recharge immediately. 

Here’s a UI table!

State Action Result
Off Hold Moon
Off Click On (Mode Memory)
On Hold Mode advance (LMH)
Any Double click Turbo
Turbo or Strobe Click Previous state
Any Click 3x Strobe
Off Click 4x Lockout
Lockout Click Main emitter flashes 2x to indicate lockout
Lockout Click 4x Unlock (to mode memory)
Lockout Hold Momentary moonlight mode

LED and Beam

Sofirn is using a Luminus SST-40 emitter in the SC18. This emitter is coupled with a TIR, and offers a great beam profile.

Wurkkos WK03 flashlight emitter and tir

Wurkkos WK03 flashlight emitter on

Wurkkos WK03 flashlight emitter on

LED Color Report (CRI and CCT)

CCT for this Luminus SST-40 is fairly cool at around 6500K.  CRI is low too, at under 70.


These beamshots are always with the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure.

Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)

I keep the test flashlight on the left, and the BLF-348 reference flashlight on the right.

I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!



What I like

  • Very low cost!
  • USB-C charging
  • C to C charging works great
  • Very nice beam profile
  • Cell included for just $2 extra, still under $17
  • Indicating switch

What I don’t like

  • Very cool CCT
  • Lockout goes to main modes (memory)
  • No tailcap magnet


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2 thoughts on “Wurkkos WK03 Flashlight Review”

  1. Aside from the body knurling, is there any significant difference between the Wurkkos WK03 and the Sofirn SC18? (I have a WK03.)

    I think they could be the next budget Wurkkos FC11. I’m not crazy about all these SST-40s Sofurrkos is putting in their lights these days, however.

    1. There is no difference that I can see!

      I read that these take some Convoy parts very well… reflectors, maybe? So a great starting point for mods, for certain!

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