Loop Gear SK-03 Flashlight Review
The Loop Gear SK-03 flashlight can run one 14500 cell (included) and can run one AA cell, too. It features an interesting “e-tritium” and an e-switch. Read on!
Official Specs and Features
Here’s a link to the Loop Gear SK-03 flashlight product page.
Versions
There are so many versions of the Loop Gear SK-03 flashlight! There are a few “basic” aluminum versions but also some special metals. Titanium, zirconium, and stainless steel, to name a few.
Price
The aluminum version of the Loop Gear SK-03 flashlight starts at $60. There are a few accessories that you can add. The tool pocket clip adds another $60. The sleeves are available separately, too.
What’s Included
- Loop Gear SK-03 flashlight
- Charging cable
- Pocket clip
- Tool pocket clip
- Color sleeves
- Spare o-ring
- Manual
Package and Manual
The kit doesn’t ship all in one box – I received these four parts separately as seen below.
Build Quality and Disassembly
The Loop Gear SK-03 flashlight is an interesting little light! I don’t say “little” casually – this is a tiny light! It’s even surprisingly small.
The next neat thing is the yellow parts you can see above. These are “e-tritium” and are just side-LEDs but that are active with very low glow when the light is off (and an 14500 is in). It’s a very neat feature!
Below, you can note a few things. First, there’s a nice beefy spring. Second, the threads are unanodized. Finally, you can see the inner tube that allows the tail e-switch to work.
The head end has just a button for contact.
Aside from the light just generally feeling (in hand) like there’s a lot going on, the build quality is good.
Size and Comps
76.5mm x 21.5mm and 45g for the aluminum version.
If the flashlight will headstand, I’ll show it here (usually the third photo). If the flashlight will tailstand, I’ll also show that (usually in the fourth photo).
Here’s the test light with the venerable Convoy S2+. The version below is a custom laser-engraved Convoy S2+ host by GadgetConnections.com. I did a full post on an engraved orange host right here! Or just go straight to GadgetConnections.com to buy your Convoy S2+ now!
Also above is the light beside a TorchLAB BOSS 35, an 18350 light. I reviewed the aluminum version of that light in both 35 and 70 formats. I also reviewed that specific edition, the “Oveready BOSS FT Collector Vintage Brass” 35. I love it!
Retention and Carry
There are two pocket clips available for the Loop Gear SK-03 flashlight. First is the standard two-way friction-fit pocket clip. It fits on the tail end only (but again, it’s a two-way clip.)
There’s also an accessory clip available as a separate purchase. It is a collar clip and will thus be more securely connected to the SK-03 but the clip is hinged. You can see in the photos below how this might be less than ideal for pocket carry (but great for other things.)
This clip hinges quite far away from the light.
Not only can this attachment be used as a platform for pointing the light in directions, but it has a couple of magnets, too.
You can use these magnets to attach to all sorts of things!
One more trick up the sleeve of this attachment is that there’s a bottle opener and box opener tucked away in there!
One final bonus here is that this accessory is full of tritium slots!
Power and Runtime
A 14500 lithium-ion cell is included for running the Loop Gear SK-03 flashlight.
The cell goes into the light with the positive end toward the head.
Below you can see a few runtime tests with the included 14500 cell. Output is lower than the claimed 1000 lumens. If this was the Nichia 519a version the 530 lumens would be reasonable, but since this is (apparently) the Philips version, this is a bit low. Further, the stepdown from turbo is quite dramatic!
The light did shut off with low voltage protection in every case.
Charging
While the light itself does not have built-in charging, the included cell does. That’s by way of USB-C charging in the positive end of the cell.
Loop Gear includes a USB to USB-C charging cable.
Charging looks good and is very conservative at around 0.5C.
Modes and Currents
| Mode | Mode Claimed Output (lm) | Claimed Runtime | Measured Lumens |
|---|---|---|---|
| Turbo | 1000 – 220 | 30s + 2.5h | 693 (0s) 530 (30s) |
| High | 220 | 2h35m | 179 (0s) 177 (30s) |
| Medium | 70 | 10h | 72 |
| Low | 7 | 50h | 8.6 |
Pulse Width Modulation
Below you can see PWM charts for the included 14500 cell (top row). The last two photos are PWM for the side light. The second row is the same, but for an AA cell.
Here you can see a “baseline” – a chart with almost no light hitting the sensor. Then there’s the Ultrafire WF-602C flashlight, which has some of the worst PWM I’ve seen. It’s so bad that I used a post about it to explain PWM! Here are multiple timescales (10ms, 5ms, 2ms, 1ms, 0.5ms, 0.2ms) to make comparing this “worst” PWM light to the test light easier. That post also explains why I didn’t test the WF-602C at the usual 50us scale.
User Interface and Operation
All operation of the Loop Gear SK-03 flashlight is via this tail e-switch. The switch has a nice metal cover and while very proud, is also completely flat. Thus, the SK-03 can tailstand.
The switch action isn’t as deep as you think it would be (and that’s fine.)
The user interface is straightforward for the main light but of course, the side lights add some wrinkles.
Here’s a user interface table!
| State | Action | Result |
|---|---|---|
| Off | Click | On (mode memory, excluding turbo) |
| On | Click | Off |
| On | Hold | Mode advance (LMH) |
| Any | Double click | Turbo |
| Any | Triple click | Strobe |
| Strobe | Hold | Strobe advance (Strobe – SOS – Beacon) |
| Off | Click 5x | Iterate off/on Micro Light mode (e-tritium) |
| Off | Click 8x | Iterate lock/unlock |
| Lockout | Hold | Momentary output |
| Off | Hold 1s | Side light on (does not come on until after switch is released) |
| Side light on | Hold | Side light advance (Low – High – Beacon) |
| Side light on | Click | Off |
LED and Beam
The emitter here is a Philips LED, but otherwise unstated. It’s a cool white version and uses a very shallow TIR. The TIR has a texture and a good beam shape because of it.
The side lights effectively have three settings – e-tritium, Low, and High. The e-tritum level is VERY low but also is very reminiscent of actual tritium. You can also get four sleeves that flex to fit over the body. This colors the side light output. It’s neat but the plastic is hard and has to be flexed open to fit over the light. I can see these breaking eventually, though I didn’t have that problem myself. Anyway I prefer the light without this accessory.
LED Color Report (CRI and CCT)
CRI and CCT are “as expected” for this Philips emitter. Not really “as claimed” maybe, since Loop Gear states this is a 6500K emitter. It measures much warmer, at around 5500K. CRI is low. These values aren’t appreciably different between 14500 and AA output.
Beamshots
These beamshots are always with the following settings: f8, ISO100, 0.3s shutter, and manual 5000K exposure. These photos are taken at floor level and the beam hits the ceiling around 9 feet away.
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!
Summary and Conclusion
The Loop Gear SK-03 flashlight is a very neat gadget! I love how small the light is. Even among 14500 flashlights, the SK-03 is small! Not only is it small, but it’s fantastic that it can run 14500 (4.2V) and AA (1.5V) cells. The user interface is fine. I love the side lights but in particular, I love the e-tritium feature. If you need a bottle opener, the $60 accessory is probably reasonable, but otherwise, the two-way clip is the way to go. For around $60, this Loop Gear SK-03 flashlight brings plenty of gadgetry!
The Big Table
| Loop SK03 | |
|---|---|
| Emitter: | Philips LED |
| Price in USD at publication time: | $119.98 |
| Cell: | 1×14500 |
| Runtime Graphs | |
| LVP? | Yes |
| Switch Type: | E-Switch |
| Quiescent Current (mA): | ? |
| On-Board Charging? | Yes |
| Charge Port Type: | USB-C (on cell) |
| Charge Graph | |
| Power off Charge Port | No |
| Claimed Lumens (lm) | 1000 |
| Measured Lumens (at 30s) | 530 (53% of claim)^ |
| Candela per Lumen | 3.6 |
| Claimed Throw (m) | 120 |
| Candela (Calculated) in cd (at 30s) | 126lux @ 3.822m = 1841cd |
| Throw (Calculated) (m) | 85.8 (71.5% of claim)^ |
| Claimed CCT | 6500 |
| Measured CCT Range (K) | 5400-5700 Kelvin |
| Item provided for review by: | Loop |
| All my Loop reviews! | |
^ Measurement disclaimer: Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.
What I like
- Very gadgety
- Side “e-tritium” lights
- Reasonable user interface
- Complete package (includes 14500)
- Runs both 14500 and AA
What I don’t like
- Accessory cost
- Cool white and low CRI output
- Didn’t hit output claim (even briefly)
Notes
- This content originally appeared at zeroair.org. Please visit there for the best experience!
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